The four-star U.S. general who leads the NATO mission to Afghanistan was present during an attack Thursday that wounded two Americans and killed an Afghan general who was key to holding together the many disparate political groups and security forces in the country’s south.

Army Gen. Scott Miller, Resolute Support commander, was present at a routine meeting with regional leaders in Kandahar, Afghanistan, when what appears to be an insider attack occurred. Kandahar police chief Gen. Abdul Raziq, a critical part of Afghanistan’s security, was targeted in the attack and killed.

“Today I lost a great friend Lt. Gen. Raziq," Miller said via Twitter. "We had served together for many years. Afghanistan lost a patriot, my condolences to the people of Afghanistan. The good he did for Afghanistan and the Afghan people cannot be undone.”

Col. Knut Peters, a Resolute Support spokesman, told Military Times the incident took place at Kandahar Palace and was an "Afghan-on-Afghan incident."

“Two Americans were wounded in the cross-fire and they have been medically evacuated,” Peters said.

A third individual working as a contractor for the NATO coalition was also wounded.

“General Miller is uninjured,” Peters added. “We are being told the area is secure. Initial reports also say the attacker is dead.”

The wounded are in stable condition, Lt. Col. Kone Faulkner, a Resolute Support official, said in a follow-on statement. The three wounded include one U.S. military service member, one U.S. civilian and one contractor of an unknown nationality.

The Taliban claimed responsibility for the attack. Taliban spokesman Zabihulla Mujahid said over social media that an “infiltrator” opened fire inside the governor’s house during a meeting.

Sources told TOLO News that Raziq was killed when assailants struck the U.S. and Afghan group after a high-profile meeting at the governor’s office.

“Raziq is basically the glue that has kept security forces in southern Afghanistan together,” Bill Roggio, a senior fellow at the Foundation for the Defense of Democracies and editor of the Long War Journal, told Military Times.

“His death is a significant blow to efforts to secure Kandahar province,” Roggio said.

Raziq is often characterized as a U.S.-backed warlord in Afghanistan. He was able to hold disparate political groups together and lead military victories against the Taliban.

But his death could bring significant upheaval in the region, which is loosely unified by figures like Raziq.

“Look, this is significant,” Roggio said. “These guys, what they tend to do, is consolidate power, and they don’t have a successor because they worry that someone wants to take their job.”

In the past, when warlord figures have been assassinated, security situations have deteriorated quickly in southern Afghanistan.

Kandahar is vital province in the country. It is an important home to members of Afghanistan’s largest ethnic group, the Pashtuns, and holds spiritual significance to the Taliban.

Kandahar lies at the epicenter of southern Afghanistan, where the Taliban have historically remained strong. It is bordered by the volatile Helmand province in the west and Uruzgan province in the north.

The area is also strategically important due to an international airport, agricultural and industrial infrastructure and major trading hubs.

Meanwhile, in Afghanistan’s north, NATO troops survived a separate attack this week, officials confirmed to Military Times.

On Wednesday, a car bomb detonated near a Resolute Support patrol outside Bagram Air Base, but “well away from a Bagram gate," Navy Cmdr. Grant Neeley, a Resolute Support spokesman, said in an email.

“Initial reports from the VBIED incident indicated six Czech soldiers were wounded,” Neeley said. “Three returned to duty fairly quickly. Three others are still receiving treatment. Also something to note, four Afghan civilians were wounded by the explosion, including one child.”

“Yet again, the Taliban are indiscriminately using explosives that injure and kill innocent civilians,” Neeley added.