BEIRUT (AP) -- Islamic State militants ambushed Syrian government forces in the country's desert, setting off two days of clashes that killed over two dozen soldiers, a war monitoring organization said Saturday.
A pro-government militia confirmed the ambush, saying it had sent its fighters to liberate the two besieged battalions.
The Islamic State group lost its last territories in Syria in March after months of battles with U.S-backed Kurdish-led fighters in the eastern province of Deir el-Zour.
But the militants remain active in the desert to the west of Deir el-Zour, where they have taken refuge and increasingly targeted government troops and allied militia.
The Syrian Observatory for Human Rights said IS militants ambushed government forces in the desert of central Homs province Thursday night, setting off clashes that lasted for two days. The Observatory said at least 27 soldiers were killed, including four officers.
Liwa al-Quds, a pro-government militia, said its fighters deployed to the desert area to liberate 500 soldiers besieged east of al-Sukhna town. In a Facebook post, the militia said it successfully broke the siege and liberated the surviving soldiers, before pulling the bodies of those killed and damaged vehicles to safety.
Liwa al-Quds, one of the elite militias operating side by side with government troops, didn't give a casualty figure.
Activists have reported a rise in clashes between government forces and allied troops and IS militants following the end of the extremist's presence in the nearby Deir el-Zour province.
The militant group, which once controlled large swathes of territory in Syria and Iraq, has kept a network of sleeper cells active in both countries.
It has also kept up its media operations. The IS-affiliated Aamaq news agency reported the attack east of al-Sukhna, adding that in 24 hours of clashes its militants killed nearly two dozen Syrian soldiers and officers. It said the militants also seized Syrian government ammunition and vehicles.