The nearly five-year war that has devastated cities and towns across north Syria and Iraq ended in Baghouz, a minor border village where the cornered militants made their last stand, under a grueling siege for weeks.

On Saturday, the Syrian Democratic Forces raised their bright yellow banner from a shell-pocked house where the militants once flew their notorious black flag. Below it stretched a field shattered by the battle, pitted by trenches and bomb craters and littered with scorched tents, twisted wreckage of burned out vehicles, unspent explosives and few remaining corpses.

“Baghouz is free and the military victory against Daesh has been achieved,” tweeted Mustafa Bali, a spokesman for the Kurdish-led SDF, referring to ISIS by its Arabic acronym.

The fall of Baghouz brings to a close a nearly 5-year global campaign against the Islamic State group that raged in two countries, spanned two U.S. presidencies and saw a U.S.-led coalition unleash more than 100,000 strikes. The campaign has left a trail of destruction in cities in Iraq and Syria, likely killed tens of thousands and drove hundreds of thousands from their homes.

The campaign put an end to the militants’ proto-state, which at its height four years ago was the size of Britain and home to some 8 million people. But the extremist group still maintains a scattered presence and sleeper cells across Syria and Iraq. It’s not known whether the group’s leader, Abu Bakr al-Baghdadi, is still alive or where he might be hiding.

ISIS affiliates in Egypt’s Sinai Peninsula, Afghanistan and other countries continue to pose a threat, and the group’s ideology has inspired so-called lone-wolf attacks that had little if any connection to its leadership.

The “caliphate’s” end also marks a new phase in Syria’s civil war, now in its ninth year. The country is carved up, with the Iranian- and Russian-backed government of President Bashar Assad controlling the west, center and south, the U.S.-backed Kurdish-led forces holding the north and east, and Turkish allies controlling a pocket in the north. The fear now is of new conflict among those players.

At a ceremony held later Saturday at the nearby al-Omar oil field base, a senior U.S. diplomat, William Roebuck, said the territorial defeat of the Islamic State group is a “critical milestone” that delivers a crushing and strategic blow to the extremist group. But he stressed it remains a significant threat.

“We still have much work to do to achieve an enduring defeat of IS,” he said.

The commander in chief of the SDF, Gen. Mazloum Abdi, appealed for continued assistance to his group until the full eradication of the extremist group. He spoke at the ceremony during which fighters marched to a military band.

The victory declaration sets the stage for President Donald Trump to begin withdrawing most of the 2,000 U.S. troops stationed in northern Syria, as he abruptly announced in December that he would do. Trump, however, later agreed to leave a small peacekeeping force of 200 soldiers in Syria to ensure Turkey will not get into a conflict with the SDF. Turkey views Kurdish members of the SDF as terrorists.

The Kurds fear being abandoned by the Americans. They are squeezed between a belligerent Turkey from the north, which regards them as a national threat and Syrian President Bashar Assad’s forces from the south.

Saturday’s announcement came a day after Trump declared that Islamic State militants no longer control any territory in Syria, a victory he had been teasing for days.

Associated Press journalists in Baghouz on Saturday, however, reported hearing mortars and gunfire directed toward a cliff overlooking the village, where U.S.-led coalition airstrikes were carried out a day earlier. SDF spokesman Kino Gabriel said Friday there were ISIS fighters hiding in caves near Baghouz and that clearing operations were still underway.

The site of ISIS’s last stand was centered on a tent encampment in Baghouz where, unknown to the besieging SDF forces, thousands of civilians were holed up. During the weeks-long siege, an estimate 30,000 men, women and children were evacuated from the pocket, most of them ISIS family members, a mix of Syrians, Iraqis and foreigners. They were exhausted, hungry, many of them wounded and traumatized by the loss of relatives, but some remained die-hard supporters of the “caliphate.”

On Saturday, journalists were taken to the encampment — a wasteland of wrecked vehicles, torn tents and scorched trees. A few bodies could be seen and a faint smell of rotting corpses hung in the air.

Scattered across the dirt amid empty foxholes and trenches were personal belongings, blankets, generators, oil barrels, water tanks and satellite dishes. Cars and motorcycles were turned to rusted, twisted heaps of metal. There were unused rockets, mortars and grenades, as well as a pile of suicide vests.

Ciya Kobani, an SDF commander, announced the end of the operation from the roof of the building with the SDF flag: “We have been victorious against Daesh,” he declared.

At its height, the Islamic State group ruled a third of both Syria and Iraq, holding millions hostage to its harsh and violent interpretation of Islamic law. The group carried out massacres and documented them with slickly produced videos circulated online. It beheaded foreign journalists and aid workers and burned alive a captured Jordanian pilot. During a rampage through Iraq’s Sinjar region in 2014, it captured thousands of women and girls from the Yazidi religious minority and forced them into sexual slavery. Many remain missing to this day.

The group also used its caliphate as a launchpad for attacks around the globe, including the assaults in Paris in 2015 that killed more than 130 people.

French President Emmanuel Macron tweeted that “a major danger to our country is now eliminated, yet the threat remains and the fight against terrorist groups must continue.” France has been a member of the coalition fighting the ISIS since 2014.

While it imposed its unforgiving interpretation of Islamic law through public beheadings and crucifixions, the group also carried out the mundane duties of governance in its territories, including regulating prices at markets and repairing infrastructure.

Cornered in Baghouz, the group fought fiercely and desperately to hang on to the last shred of territory it controlled, using thousands of civilians, including women and children, as human shields. In the final weeks, they streamed out of Baghouz, bedraggled, angry and hungry, overwhelming Kurdish-run camps in northern Syria where they are being held.

Aid organizations say more than 100 people have died in the journey from Baghouz to the al-Hol camp in Hassakeh province, or soon after arriving.

Associated Press writer Zeina Karam in Beirut contributed to this report.

The long-running battle to retake the last outpost held by ISIS in eastern Syria appeared to have reached its conclusion, with no signs of battle Wednesday, although officials said a few remaining ISIS militants still had not surrendered.

Ciyager Amed, an official with the Kurdish-led Syrian Democratic Forces, said they were searching for any ISIS militants hiding in tunnels in a riverside pocket in the village of Baghouz. The SDF held back on announcing victory over ISIS.

Associated Press journalists saw SDF soldiers loading women and children into trailer trucks on the hilltop over Baghouz, in a sign evacuations were ongoing Wednesday. Black smoke could be seen rising from the village.

The SDF on Tuesday seized control of the encampment held by ISIS after hundreds of militants surrendered overnight, signaling the group’s collapse after months of stiff resistance. Fighters celebrated after months of grueling battles and an on-again off-again offensive that saw thousands of people, many of them women and children, evacuated from the pocket.

The militants have been putting up a desperate fight, their notorious propaganda machine working even on the brink of collapse.

The complete fall of Baghouz would mark the end of the Islamic State group’s self-declared caliphate, which at its height stretched across large parts of Syria and Iraq. For the past four years, U.S.-led forces have waged a destructive campaign against the group. But even after Baghouz’s fall, ISIS maintains a scattered presence and sleeper cells that threaten a continuing insurgency.

The battle for Baghouz has dragged on for weeks and the encampment had proven a major battleground, with tents covering foxholes and underground tunnels.

The siege has also been slowed by the unexpectedly large number of civilians in Baghouz, most of them families of ISIS members. Over past weeks they have been flowing out, exhausted, hungry and often wounded. The sheer number who emerged — nearly 30,000 since early January, according to Kurdish officials — took the SDF by surprise.

The taking of the ISIS camp was a major advance but not the final defeat of the group in Baghouz, the last village held by the extremists where they have been holding out for weeks under siege, according to Mustafa Bali, the spokesman for the Kurdish-led force known as the Syrian Democratic Forces. Still, fighters from the force were starting to celebrate anyway.

“I’m happy it’s over. Now I know my people are safe,” said a fighter who identified himself as Walid Raqqawi who fought in the camp Monday night. He said he is returning to his hometown of Raqqa to rest. Comrades from his unit sang and danced in celebration at an outpost in Baghouz, all saying they were looking forward to going home.

An unknown number of ISIS militants still clung to a tiny sliver of land trapped between the Euphrates River and the encampment now held by the SDF, officials in the force said.

The militants have been putting up a desperate fight, their notorious propaganda machine working even on the brink of collapse. On Monday, ISIS issued a video showing its militants furiously defending the encampment, a junkyard of wrecked cards, motorcycles and tents. In the footage, they shoot nonstop with AK-47s and M-16s from behind trucks, vehicles and sand berms.

A group of children could be seen at one point amid the fighting.

“My Muslim brothers everywhere, we did our best, the rest is up to God,” a fighter says as black smoke rises from behind him.

The complete fall of Baghouz would mark the end of the Islamic State group’s self-declared territorial “caliphate,” which at its height stretched across much of Syria and Iraq. For the past four years, U.S.-led forces have waged a destructive campaign to tear down the “caliphate.” But even after Baghouz’s fall, ISIS maintains a scattered presence and sleeper cells that threaten a continuing insurgency.

The battle for Baghouz has dragged on for weeks — and the encampment has proven a major battleground, with tents covering foxholes and underground tunnels.

The siege has also been slowed by the unexpectedly large number of civilians in Baghouz, most of them families of ISIS members. Over past weeks they have been flowing out, exhausted, hungry and often wounded. The sheer number who emerged — nearly 30,000 since early January according to Kurdish officials — took the Kurdish-led SDF by surprise.

In the last two weeks, many ISIS militants appeared to be among those evacuating. But SDF commanders have stopped speculating when the battle may finally be over. Commanders say they don’t know how many more may still be left, hiding in tunnels beneath the war-scarred village.

In the seizure Tuesday of the encampment, hundreds of wounded and sick militants were captured and have been evacuated to nearby military hospitals for treatment, Bali, the SDF spokesman, said in a Twitter post. Still, he cautioned, “this is not a victory announcement, but a significant progress in the fight.”

There were conflicting reports from SDF commanders on the ground about the extent of the ISIS surrender.

Commander Rustam Hasake told The Associated Press that SDF forces advanced on four fronts Monday night and were inside the camp when the last ISIS fighters surrendered at dawn. He said the last fighters were pushed out of the camp and were now in an open patch of land by the Euphrates River and were being processed and detained.

Another commander, however, said some ISIS militants continue to hold a tiny area in an open patch of land in the village, outside the encampment.

AP journalists in Baghouz reported sporadic gunfire echoing in Baghouz and jets circling overhead. At a command post in Baghouz, a Humvee pulled up and unloaded weapons captured from ISIS on Tuesday, including sniper and hunting rifles, pump action shot guns and grenades and ammunition.

Five trucks hauling 10 trailers full of people were seen coming out of Baghouz. A child could be heard wailing from inside one of them. At least 100 people, nearly all of them children, have died in the truck trips from Baghouz on the way to a camp in northern Syria, or soon after reaching it, according to the International Rescue Committee — a sign of how miserable conditions were inside Baghouz during the siege as supplies ran out.

Bali, in a separate Twitter post Tuesday, said the SDF captured a group of suspects involved in a January suicide bombing that killed four Americans in the northern town of Manbij. He did not elaborate on the number of suspects or whether they were among the most recent militants to surrender.

The Islamic State group claimed responsibility for the blast outside a popular restaurant in Manbij, which killed at least 16 people, including two U.S. service members and two American civilians. It was the deadliest assault on U.S. troops in Syria since American forces went into the country in 2015.

As they make their final stand, the ISIS militants have issued a string of statements this month claiming to have inflicted heavy losses on the SDF.

In an audio posted online Monday, the ISIS spokesman, Abu Hassan al-Muhajer, issued his first message in six months, calling for revenge attacks by Muslims in Western countries in retaliation for the shooting attack on two New Zealand mosques that killed 50 people.

He also ridiculed U.S. declarations of the defeat of the Islamic State group, calling the claim of victory a “hallucination.”

But SDF fighters celebrated as if the final collapse were imminent. At the SDF outpost in Baghouz, a commander danced with his soldiers. Fighters said remaining ISIS militants didn’t put up much resistance.

“We fired on them with our rifles and heavy weapons and they didn’t shoot back. So we walked into the camp and they didn’t shoot at us,” said Orhan Hamad, from the northern province of Hassakeh.

“I tell the martyrs, it wasn’t for nothing. With God’s permission, we’ve finished Daesh.”

Associated Press writer Maamoun Youssef in Cairo and Zeina Karam in Beirut contributed reporting.

The battle to capture the extremist group’s last patch of territory in eastern Syria — a collection of tents covering foxholes and underground tunnels in the village of Baghouz — has dragged on for weeks amid an unexpected exodus of civilians from the area.

The sheer number of people who have emerged from Baghouz, nearly 30,000 since early January according to Kurdish officials, has taken the Kurdish-led Syrian Democratic Forces by surprise. Most have been women and children whose existence in a labyrinth of underground caves and tunnels was unknown to the fighters.

In the last two weeks, many fighters appeared to be among those evacuating. But an unknown number of militants and civilians remain inside, refusing to surrender.

“We are facing several difficulties regarding the operations,” SDF commander Kino Gabriel told reporters outside Baghouz on Sunday.

He cited the large number of mines and explosive devices planted by ISIS and the existence of tunnels and hideouts beneath the ground that are being used by the militants to attack SDF forces or defend themselves.

The camp is all that remains of a self-declared Islamic “caliphate” that once sprawled across large parts of Syria and neighboring Iraq. But a declaration of victory and the group’s territorial defeat has been delayed as the military campaign sputtered on in fits and starts.

A final push by Kurdish-led Syrian Democratic Forces started on Jan. 9 but has been paused on several occasions, mainly to allow for civilians to evacuate and fighters to surrender.

Underscoring the struggles faced by the SDF as they try to flush the out extremists, three ISIS fighters emerged from Baghouz on Friday acting as though they wanted to surrender only to blew themselves up, killing six people.

The campaign has also been hindered by bad weather. Intermittent storms have at times turned the battlefield to mud and ISIS militants have mounted counteroffensives on windy days, burning tires and oil to try to force the SDF back with smoke.

On Sunday, dozens of men and women were seen walking around the besieged IS encampment in Baghouz, as SDF fighters watched from a hilltop close by.

The camp, looking much like a junkyard, was littered with damaged vans and pickup trucks parked between tents where people appeared to be moving about.

On the hilltop lookout north of Baghouz, an SDF sentry, lying flat on his stomach with his rocket launcher trained on the camp, cautioned an approaching comrade not to get too close. “There are snipers,” he said of the ISIS camp.

Gabriel said the camp was approximately 0.25 square kilometers in size — much the same area it was five weeks ago, when the SDF said it was finally going to conclude the battle.

In the middle of the camp stands a pair of two-story compounds, showing little sign of damage. Several houses that appeared habitable can be seen as well.

With operations now stretching into the spring, Gabriel faced pointed questions from the press over whether ISIS would be able to resupply itself with water and goods, despite the siege.

He said he was not aware of any smuggling tunnels still in operation, and that ISIS was cut off from the outside world.

“I don’t think we will be seeing more ISIS terrorists appearing in this pocket, he said.

A commander participating in operations on the western side of the enclave said he did not believe ISIS was fleeing to the other side of the Euphrates River either, where Syrian government forces and their allies are holding positions.

Gabriel said 29,600 people have left Baghouz since Jan. 9, among them 5,000 fighters — far greater than the SDF had initially estimated remained inside.

He said the SDF no longer estimates how many people remained in Baghouz but added that recent evacuees told the fighting forces that another 5,000 were still inside.

The force and the Kurdish-led authorities that administer northeast Syria have banned in recent days journalists from interviewing evacuees from Baghouz.

The evacuees are now living in detention-like camps in the self-administered region that international humanitarian organizations say are vastly overcrowded and underserved. They say disease is rampant in the camps and medical care is desperately needed.

“The Daesh terrorists are starting to feel hunger and thirst and we are seeing this in the people who are coming out of the camp,” said Gabriel, using the Arabic acronym for ISIS.

BAGHDAD — A U.S. defense official says no American troops have withdrawn yet from Syria, but some military cargo has been pulled out.

The official said the movement of equipment is part of what the military calls the start of a deliberate withdrawal from Syria, where about 2,000 troops have been working with a coalition of Syrian Kurdish and Arab fighters to defeat the remnants of the Islamic State group.

The official spoke on condition of anonymity to discuss details that have not yet been publicly announced.

The official provided no numbers, but said the equipment withdrawal is under way and that an unspecified number of additional U.S. troops have been brought into Syria to assist with the withdrawal process. These include troops to provide additional security.

This is a clarification after news reports early Friday that the U.S. has begun a “deliberate withdrawal” from Syria. After days of conflicting statements about a timeline for President Donald Trump’s decision to pull out American troops from Syria, a U.S. military official said Friday that the withdrawal process has begun, declining to comment on specific timetables or movements.

Army Col. Sean Ryan, spokesman for the U.S.-led coalition fighting the Islamic State group, said in earlier reports that “the process of our deliberate withdrawal from Syria” has started.

“Out of concern for operational security, we will not discuss specific timelines, locations or troops movements,” the Baghdad-based official said in a statement emailed to The Associated Press.

There were no other details, and it was not immediately clear how many vehicles or whether any troop units had withdrawn.

The Britain-based Syrian Observatory for Human Rights, which monitors the conflict in Syria through a network of activists on the ground, said the withdrawal began Thursday night. It said a convoy of about 10 armored vehicles, in addition to some trucks, pulled out from Syria’s northeastern town of Rmeilan into Iraq.

Confirmation of the first withdrawals comes amid confusion over plans to implement Trump’s pullout order and threats from Turkey to attack the Kurds, who have been America’s partners on the ground in the war against the Islamic State group in Syria.

Earlier this week, the U.S. National Security Adviser John Bolton said American troops will not leave northeastern Syria until IS is defeated and American-allied Kurdish fighters are protected, signaling a slowdown in Trump’s initial order for a rapid withdrawal.

A senior Kurdish politician said the Kurds are aware of the U.S. beginning its withdraw process, describing it as “America’s decision.”

“The Americans have a right to make decisions that are in their country’s security and national interests,” said Ilham Ahmed, who co-chairs the U.S.-backed Syrian Democratic Council in northeast Syria. But the peace and stability of areas U.S. forces withdraw from “must be guaranteed,” she added. This, she said, includes putting an end to the Turkish threats and fully eradicating the Islamic State group and its sleeper cells.

There are 2,000 American troops in Syria. Trump’s abrupt decision in December to pull them out, declaring in a tweet the defeat of IS, sent shock waves across the region and a flurry of criticism from some of his generals and national security advisers, and led to the resignation of U.S. Defense Minister James Mattis and the top U.S. envoy to the anti-IS coalition. It also led to major criticism that the U.S. was abandoning its local Kurdish allies amid Turkish threats of an imminent attack.

On Sunday, Bolton said American troops will not leave northeastern Syria until IS is defeated and American-allied Kurdish fighters are protected, signaling a slow-down in Trump’s initial order for a rapid withdrawal. Secretary of State Mike Pompeo, who is on a tour of the region, has also sought to reassure the Kurds that they will be safe after U.S. troops withdraw from the country.

“These have been folks that have fought with us and it’s important that we do everything we can to ensure that those folks that fought with us are protected,” Pompeo said of the Kurds while visiting Irbil, the capital of Iraq’s semi-autonomous Kurdistan region, after talks in Baghdad.

After initially tweeting about the decision to bring back U.S. troops “now,” Trump this week said “we will be leaving at a proper pace while at the same time continuing to fight ISIS and doing all else that is prudent and necessary!”

Kurdish officials, meanwhile, have demanded clarifications from the U.S. over its intentions. A U.S. troop pullout leaves the Kurds exposed to Turkish attacks from one side, and Syrian government troops on the other. The withdrawal benefits Syrian President Bashar Assad and his international backers, Russia and Iran, who are primed to move into the region to fill a vacuum left behind by the Americans.

Russia’s Foreign Ministry spokeswoman Maria Zakharova said the Americans are not serious about withdrawing from Syria.

Speaking to reporters in Moscow Friday, she said it appears to Moscow that the U.S. “is looking for a reason to stay.” She said Russia has not seen public statements laying out the U.S. strategy in Syria and so cannot be sure that the U.S. is serious about leaving.

U.S. troops have been involved in Syria’s war since 2014 when the first elite force arrived in the country to advise Kurdish-led fighters who were involved in battles against the Islamic State group.

Karam reported from Beirut. Associated Press writers Bassem Mroue in Beirut, Nataliya Vasilyeva in Moscow, Zeynep Bilginsoy in Istanbul and Robert Burns in Washington, DC, contributed to this report.

Politicians from both blocs of Iraq’s divided Parliament called for a vote to expel U.S. troops and promised to schedule an extraordinary session to debate the matter.

“Parliament must clearly and urgently express its view about the ongoing American violations of Iraqi sovereignty,” said Salam al-Shimiri, a lawmaker loyal to the populist cleric Moqtada al-Sadr.

Trump, making his first presidential visit to troops in a troubled region Wednesday, said he has no plans to withdraw the 5,200 U.S. forces in the country.

Containing foreign influence has become a hot-button issue in a year that saw al-Sadr supporters win the largest share of votes in May elections. Al-Sadr has called for curbing U.S. and Iranian involvement in Iraqi affairs.

U.S. troops are stationed in Iraq as part of the coalition against the Islamic State group. American forces withdrew in 2011 after invading in 2003 but returned in 2014 at the invitation of the Iraqi government to help fight the jihadist group.

But after defeating IS militants in their last urban bastions last year, Iraqi politicians and militia leaders are speaking out against the continued presence of U.S. forces in Iraqi soil.

Qais Khazali, the head of the Iran-backed Asaib Ahl al-Haq militia that fought key battles against IS in north Iraq, promised on Twitter that Parliament would vote to expel U.S. forces from Iraq, or the militia and others would force them out by “other means.”

Khazali was jailed by British and U.S. forces from 2007 to 2010 for managing sections of the Shia insurgency against the occupation during those years.

His militia is represented in Parliament by the Binaa bloc, a rival coalition to al-Sadr’s Islah. Binaa favors close ties with Iran and is aligned with Tehran on regional political issues.

Trump spent three hours at Al-Asad Air Base meeting with U.S. troops during his visit. The president defended his decision to withdraw 2,000 U.S. forces from neighboring Syria, saying the U.S. military had all but eliminated IS-controlled territory there.

He left without meeting any Iraqi officials, though he spoke to Prime Minister Adel Abdul-Mahdi by phone.

The prime minister’s office said in a statement after Trump’s visit that “differences in points of view” over arrangements led to a face-to-face meeting between the two leaders to be scrapped.

Al-Shimiri said Trump’s visit “violated several diplomatic norms.”

Separately, at least 21 pro-government fighters were killed in clashes with the militants in south Syria, underlining the persistent threat posed by the group despite its shrinking footprint.

The Britain-based Syrian Observatory for Human Rights monitoring group said the 21 fighters, among them Syrian soldiers and foreign militiamen who have been recruited to fight for President Bashar Assad, died Monday night in a battle with ISIS militants in the Safaa desert region at the edges of Sweida province.

The activist-run pro-government Facebook page Damascus Now, however, reported that only 14 fighters died in the fighting. Such discrepancies on casualty figures are not uncommon in the immediate aftermath of the fighting.

Government forces have been battling the militants in the area for weeks since ISIS fighters ambushed Sweida in July.

The militants are believed to be holding some 30 Sweida civilians captive in the Safaa area since kidnapping them in the July ambush, when some 300 people were killed during the daylong battle.

In north Syria, the Syrian Democratic Forces said it launched operations to expel ISIS militants from the town of Hajin and surrounding villages on the northeast banks of the Euphrates River.

The SDF is backed by the U.S.-led international coalition against ISIS.

The coalition said in a statement it was supporting the SDF ground operation with air and artillery strikes.

The Observatory said coalition jets have been bombing locations across the ISIS pocket in conjunction with the SDF ground offensive. At least 23 ISIS fighters were killed in the first 24 hours of battle, according to the Observatory.

Despite losing 90 percent of its territory between Iraq and Syria since its 2014 peak, the jihadist group remains a disruptive force in both countries. Its leader, the self-styled “Caliph” Abu Bakr al-Baghdadi, urged followers to “persevere” in an audio tape attributed to him last month.

Also Tuesday, Turkey’s President Recep Tayyip Erdogan urged the international community to stop the Syrian government from embarking on a widely-expected campaign to retake Idlib province from rebels.

Idlib is the last refuge for the Syrian opposition and home to close to 3 million people, including 1.4 million displaced Syrians hailing from provinces now controlled by the government.

Erdogan, in an op-ed printed in the Wall Street Journal, said an assault on Idlib would “create serious humanitarian and security risks for Turkey, the rest of Europe and beyond.”

The op-ed came as high-level diplomats from Turkey, Russia, and Iran met with the U.N. envoy for Syria about creating a committee to revise the war-battered country’s constitution, in Geneva.

Russia, Turkey and Iran have been working together as “guarantors” for a series of talks around ending Syria’s war. Turkey has taken in 3.5 million refugees from its neighbor.

Syrian government forces, backed by Russia and Iran, have been massing troops for weeks around Idlib in preparation for an attack.

Erdogan said an attack would amount to “indiscriminate attacks to wipe out its opposition and not a genuine or effective campaign against terrorism.”

Turkey’s has 12 military outposts inside Idlib province and supports various factions inside. In recent days, Turkey has moved dozens of armored vehicles across its border and into Idlib, the Observatory reported.

But Russia and Iran say they are determined to annihilate the al-Qaida-linked Hayat Tahrir al-Sham group that is the dominant fighting force in the province.

The Turkish president said Russia and Iran have the responsibility to stop the humanitarian disaster.

Associated Press writers Jamey Keaten in Geneva and Suzan Fraser in Ankara, Turkey contributed to this report.

BEIRUT — In a corner of northwestern Syria packed with nearly 3 million people, the government and its opponents are preparing for a final, bloody showdown.

The campaign for Idlib, the opposition’s only remaining stronghold in the country and now a refuge for over a million displaced Syrians, is likely to be the last major theater of battle after seven years of brutal civil war.

It is also potentially the most dangerous.

The U.N. and aid workers are bracing for disaster, warning that up to 800,000 people are in danger of renewed displacement if a government offensive gets underway. A massive military buildup in nearby areas suggests an assault — at least to regain parts of the province — may be imminent.

Turkey, which backs the rebels in Idlib, has warned against a military solution and is reportedly negotiating with Russia in an effort to avoid a full-scale offensive.

Concern is mounting meanwhile over the potential use of chemical weapons, and the Russian navy is building up its presence in the Mediterranean Sea.

Here’s a look at what lies ahead for Idlib:

THE OPPOSITION’S LAST REFUGE

After seven years of war, President Bashar Assad has largely quashed the popular revolt that erupted against his family’s decades-long rule in 2011, which was inspired by the Arab Spring protests that swept the region that year.

Idlib now amounts to the last refuge for the opposition, as well as the al-Qaida-linked insurgents that have fought alongside it.

President Bashar Assad is determined to retake Idlib, and has vowed to eventually bring all of Syria back under his government’s control.

At one point, the opposition controlled parts of Syria’s largest cities and most of the territory around Damascus, the capital. But Russia launched an air campaign in support of Assad in 2015, and Iran has sent thousands of military advisers and allied militiamen to aid his forces. In the last year alone, the government has forced its opponents out of Damascus, Homs, Daraa, and Quneitra, four provinces and cities that were longtime opposition strongholds.

As government forces advanced, they offered residents and one-time opponents the choice either to reconcile with Assad’s rule or board buses for Idlib, where al-Qaida-linked groups have eclipsed the moderate opposition.

Tens of thousands of people chose to leave to Idlib, fearing they could be face imprisonment, forced conscription, or worse at the hands of government forces.

Now they have nowhere left to turn, after other opposition pockets have collapsed, and Turkey has largely sealed its borders to new refugees.

THE CHEMICAL WEAPONS FACTOR

The U.S. State Department has said it will hold Moscow, an ally of Damascus, responsible if government forces use chemical weapons in the battle for Idlib.

U.N. investigators have already attributed several chemical attacks in Syria to government forces, including one attack using the nerve agent Sarin gas against the Idlib town of Khan Sheikhoun in April 2017.

That attack prompted the U.S. to carry out a rare strike against a Syrian military installation. In April, the U.S., France and Britain launched punitive strikes after a chlorine gas attack on a suburb of Damascus then held by the opposition. The U.S. also holds the government responsible for a Sarin gas attack that may have killed over 1,000 people in August 2013 in the Ghouta suburbs of Damascus.

Syria’s government denies ever using chemical weapons and says it disposed of its stockpiles under an agreement brokered by the U.S. and Russia after the 2013 Ghouta attack.

Chemical attacks have only accounted for a small fraction of the estimated 400,000 people killed in the civil war.

Now, Moscow and Damascus say the U.S. is planning to fabricate a chemical attack or encourage rebels to execute one, as a pretext to launch renewed strikes against Assad’s forces. But there is scant evidence that rebels have used chemical weapons in the past, and the U.S. has shown little appetite for taking forceful military action against the government.

On Tuesday, U.S. Defense Secretary James Mattis said Washington was in “active” communication with Russia about preventing another chemical attack.

A CATASTROPHE IN THE MAKING

The U.N. says a battle for Idlib would cause a humanitarian catastrophe. With Turkey closing its borders to new refugees, it is unclear where civilians might go. Many are already living in camps in Idlib amid dire conditions, with 2 million in need of humanitarian aid.

The leaders of Russia, Iran, and Turkey are slated to meet next week in the northern Iranian city of Tabriz, where many are hoping for a deal to avert a calamitous battle over Idlib.

In the meantime, the government is amassing its forces around the province, and Russia has positioned at least 10 warships and two submarines off the coast, according to Russian media reports.

If a campaign does proceed against Idlib, it is likely to follow the formula set in previous battles. Russian and Syrian warplanes would launch wave after wave of devastating airstrikes, before government forces besiege towns and cities, forcing residents to surrender or starve.

It was the second meeting between the two sides, and they agreed to continue their discussions, said Ilham Ahmed, the co-president of the Kurdish-led Syrian Democratic Council.

The SDC delegation pressed for constitutional reforms to enshrine regional self-administration, said Ahmed, who described the government’s response as “not positive.”

“We have lots of work ahead of us, and I don’t think this will be easy,” said Ahmed.

The Syrian government has vowed to reassert its rule over the whole country after surviving seven years of civil war.

President Bashar Assad is demanding the departure of U.S. troops, who are embedded with the military arm of the SDC, the Syrian Democratic Forces, in the northeast Rojava region.

U.S. forces supported the Syrian Democratic Forces in their campaign against the Islamic State group in northeastern Syria. An estimated 2,000 U.S. troops and military advisers are in northern Syria, and the U.S. operates air bases in the Kurdish-administered region.

The Trump administration remains noncommittal about its plans for northern Syria.

Ahmed said the Kurdish-run region would not participate in nationwide local elections slated for next month, despite pressure from the government.

She said the SDC delegation met with officials from Damascus’s authority on local administration and the ruling Baath Party’s National Security Bureau, which oversees all intelligence operations in Syria.

Also Tuesday, Syrian state media said five drones were shot down in the coastal Latakia province as they approached a Russian air base in the area.

The air base, known as Hemeimeem, is the headquarters for Russia’s military operations in support of Assad’s forces. Russia has been a major ally and has turned the tide of the civil war in his favor.

The Britain-based Syrian Observatory for Human Rights monitoring group says the drones were downed late Monday. It says this is the fifth time in as many days that drones have been shot down as they tried to reach the air base.

The Observatory and Syrian state media say the drones were launched by rebels holding territory in the neighboring Idlib province in northwestern Syria.

Amnesty International said the U.S.-led coalition’s 2017 assault on Raqqa killed hundreds of civilians and reduced sections of the city to rubble.

Researchers for Amnesty interviewed more than 100 residents and visited 42 coalition targets in the city in a two-week period in February. They published their findings in a report titled “War of Annihilation,” in a reference to the language used by U.S. Defense Secretary Jim Mattis in the lead-up to the campaign.

“When so many civilians are killed in attack after attack, something is clearly wrong,” said Donatella Rovera, one of the researchers who visited the city.

U.S. Army Col. Sean Ryan, spokesman for the coalition, called the assertions “grossly inaccurate.” He said the coalition and allied Syrian forces organized safe passages for residents to flee, but ISIS militants trapped them inside to use as human shields.

“When you have an enemy that uses noncombatants as collateral damage, it’s very difficult when you fight an enemy like that to completely avoid any casualties,” Ryan said.

Army Col. Thomas Veale, another spokesman for the coalition, accused Amnesty of a “failure to check the public record and get facts straight.”

Speaking to reporters at the Pentagon by videoconference from Baghdad, Veale disputed what he said was the group’s assertion that the coalition had violated international law.

“In other words, they are literally judging us guilty until proven innocent,” he said. “That’s a bold rhetorical move by an organization that fails to check the public record or consult the accused.”

Benjamin Walsby, another investigator on the Amnesty team, said the coalition should have adjusted its strategy.

“If you rely on long-range tactics like artillery and airstrikes, then civilians are very likely to pay the price, and that appears to be what happened in Raqqa,” he said.

The battle for Raqqa, once a city of 200,000 people, played out over four harrowing months in 2017, with the coalition playing a supporting role as the Kurdish-led Syrian Democratic Forces fought street by street.

The coalition unleashed wave after wave of airstrikes and shell fire until the last of the militants left Raqqa in October 2017.

Command Sgt. John Wayne Troxell of the U.S. Army said in January that U.S. Marines had fired 30,000 artillery shells on the city.

When The Associated Press visited in April, it found Raqqa in ruins and its streets smelling of rotting bodies. Civil workers had pulled nearly 500 corpses from the rubble and were still finding more six months after the fighting.

Residents complained that the coalition bombing was indiscriminate and demanded compensation. According to the Raqqa Civil Council, which took over the administration of the city, 65 percent of homes had been destroyed.

ISIS militants booby-trapped the city, leaving streets and homes too dangerous for immediate reoccupation.

In its monthly casualty reports, the coalition has acknowledged responsibility for 32 civilian deaths in Raqqa between June and October, while saying it is still investigating open cases. Ryan, the coalition spokesman could not say whether officials were interviewing relatives of the deceased as part of their investigations.

Amnesty International’s report says hundreds of civilians were killed, while the Airwars monitoring group says it has evidence of 1,400 fatalities.

Amnesty investigators called on the coalition to release strike data and details on the decision-making process behind target selection. They said the coalition rebuffed requests for information.

“It doesn’t matter how precise your strikes are. They are only as precise as the information behind them, and if the information isn’t right you’re going to shoot at the wrong things,” Walsby said, adding that a thorough investigation could build a case for a war crimes trial.

The State Department said in a release that the coalition applies rigorous standards to its targeting process.

It “has been transparent about its process for conducting strikes and assessing any allegations of civilian casualties that may have resulted from those strikes,” it said.

Ryan said the coalition was never contacted by Amnesty.

The coalition maintains that it relied on precision weapons and selected targets with the best information available and that it did everything it could to minimize civilian casualties.

“I would put the blame on ISIS for destroying the city,” Ryan said. “We liberated the city of Raqqa. The city deserves better and we’re going to try to provide that.”

Associated Press writers Robert Burns and Josh Lederman in Washington contributed.