A US soldier stands in an armoured personnel carrier as the US forces pull out of their base in the Northern Syrian town of Tal Tamr, on October 20, 2019. - US forces withdrew from a key base in northern Syria today, a monitor said, two days before the end of a US-brokered truce to stem a Turkish attack on Kurdish forces in the region. (Photo by Delil SOULEIMAN / AFP) (Photo by DELIL SOULEIMAN/AFP via Getty Images)
CNN  — 

US troops in Syria and their allies exchanged fire with pro-Syrian regime forces in the eastern part of the country.

A convoy of US troops and Syrian Democratic Forces were fired upon in eastern Syria Monday morning as they were traveling through a known checkpoint manned by Syrian pro-regime forces, the US-led coalition reported.

No US personnel were injured, according to Col. Myles Caggins, the chief spokesman for Operation Inherent Resolve, who said that the coalition forces returned fire.

“Coalition and Syrian Democratic Forces, conducting a routine anti-ISIS security patrol near Tal Al-Zahab, Syria, encountered a checkpoint occupied by pro-Syrian regime forces. After receiving safe passage from the pro-regime forces, the patrol came under small arms fire from individuals in the vicinity of the checkpoint. Coalition troops returned fire in self-defense,” Caggins said in a statement.

Helicopter convoy

While there were helicopters overhead flying standard convoy escort duty, the coalition did not conduct any airstrikes, Caggins said. The convoy then returned to base. The incident remains under investigation.

The US is not yet able to confirm Syrian casualties or that the troops that fired on them were uniformed Syrian military personnel, Caggins said.

It is not clear why the shooting began, because convoys have regularly passed through checkpoints with few incidents. The US maintains less than 1,000 troops in Syria currently to fight remnants of ISIS. They are stationed both near the eastern oil fields and at the At Tanf garrison in southeastern Syria.

The Syrian state news agency claimed that US forces attacked a checkpoint, killing one and injuring two. A Syrian military source told SANA that “at 9:45 am, a US patrol tried to enter the area where one of our military formations is deployed in Qamishli countryside through Tal al-Zahab checkpoint, and the army personnel at the checkpoint prevented it from passing, therefore, the members of the US patrol opened several rounds of fire.”