Clashes erupted between Syrian regime forces and an American patrol in the northeastern city of Qamishli, Syrian official media and the Syrian Observatory for Human Rights reported on Wednesday.
The two sources reported the death of one person but it was not immediately clear who it was. Syrian state media said it was a US soldier, while the Observatory said it was not clear whether the killed person is a civilian or an armed regime loyalist.
The US-led coalition fighting ISIS confirmed that its troops opened fire at a checkpoint in northeast Syria after they came under small arms fire but did not mention any casualties.
The clashes happened in Khirbet Amo, a village in the countryside of Qamishli city.
Armed regime loyalists stood in the way of an American patrol during its tour in the area and fired in the air, according to the Observatory, after which US forces fired a smoke grenade and shot one person. No further information was available on the killed person.
The war monitor also reported on US jets flying over the area, adding that a Russian patrol arrived on the scene to calm the situation and the US patrol was able to leave.
In a statement, the coalition said the situation was de-escalated and the patrol returned to the base.
This photograph, posted by CNN's senior international correspondent Ben Wedeman, reportedly shows the scene of the clashes.
Commentators pointed to the multiple flags present in the image as representative of the contested state of northeast Syria.
The US has around 600 troops stationed in northeast Syria, according to US Defense Secretary Mark Esper.
US President Donald Trump had announced the withdrawal of US troops from northeastern Syria in October, 2019. At the time, there were around 1,000 troops in the country.
The move was seen as a green light for Turkey and Turkish-backed Syrian fighters to launch an incursion into the region to fight against Kurdish-led Syrian Democratic Forces and establish a “safe zone” for the return of Syrian refugees from Turkey.
However, US troops remained in the region after the pullback, with Trump saying they would protect oil interests in northeast Syria.