BEIRUT — Syrian pro-government forces advanced Monday toward al-Bab, completing the encirclement of the Islamic State-held town which had been partially besieged by Turkey-backed opposition forces, state media and an activist group said.
Turkish troops and allied Syrian opposition fighters, known as Euphrates Shield, have been trying to seize the town for weeks in fighting that has killed dozens of Turkish troops. The Syrian government and the Turkish-backed forces are not coordinating their operations.
The Syrian government condemned the incursion when Turkish troops crossed the border in August. But since then Turkey has joined with Russia and Iran to guarantee a cease-fire between the government and Syrian rebels.
Both forces appear to be in a race to enter al-Bab, which lies at a strategic crossroads in northern Syria.
Turkey, which for years supported the Syrian opposition battling to overthrow President Bashar Assad, has recalibrated its priorities toward fighting ISIS militants and thwarting Kurdish aspirations for autonomous rule along Syria's border with Turkey.
Capturing al-Bab, one of ISIS's biggest strongholds in northern Syria, would allow the Turkish forces to prevent the Kurds from linking their enclaves in the west and east.
Syria's state news agency, SANA, said Monday that Syrian troops captured the Eweisheh hill, cutting al-Bab off from other areas under ISIS control. The Britain-based Syrian Observatory for Human Rights confirmed that the extremists were under siege.
The Observatory, which relies on a network of activists inside Syria, said the Syrian troops were backed by Lebanon's Hezbollah, which has sent thousands of fighters to bolster Assad's forces.
The government-controlled Syrian Central Military Media said troops are pushing north and have severed ISIS supply lines.
On Sunday, Turkish troops and Euphrates Shield fighters briefly captured the town of Bazaa near al-Bab before the extremists launched a counteroffensive. The Qasioun news agency, run by local activists, said Monday that Turkish troops and their allies launched a new offensive in an attempt to retake the town.
Elsewhere in northern Syria, the Observatory and pro-government activists said a warplane crashed near the Nairab air base in the northern city of Aleppo, killing the pilot. It was not immediately clear if the warplane was taking part in attacks against ISIS in al-Bab area.
And in Homs province, Syria's Al-Ikhbariya TV said ISIS militants blew up a gas pipeline, causing a huge fire. Government forces have been advancing in the area of the Hayan gas facility in the eastern part of the province for days.