A US outpost in southern Syria was hit with a co-ordinated drone attack on Wednesday, but there were no reports of any American casualties, officials said.
“Explosions resounded from Al Tanf base used by the US-led coalition” fighting ISIS, the Syrian Observatory for Human Rights said from Britain, without specifying who was responsible for the attack.
US officials told Reuters it was too early to say who was responsible but one said it was believed to have been a drone attack and rocket attack.
One official said one of the drone strikes hit the US side of the al-Tanf garrison, while one may have hit the side where Syrian opposition forces are based.
Al Tanf is in a strategic area near the Syrian border crossing with Iraq and Jordan.
The garrison was set up when ISIS fighters took control of eastern Syria along the border with Iraq, but after the militants were driven out, it became part of the larger US strategy to contain Iran's military reach in the region.
There was no information as to whether local troops were injured or killed in the attack, an official told AP.
Al Tanf is the only location in Syria outside the Kurdish-controlled north with a significant US military presence.
Damascus and its allies have repeatedly claimed US troops have no reason to be there.
While attacks against US troops at this outpost are uncommon, Iranian-backed forces have frequently attacked American soldiers with drones and rockets in eastern Syria and Iraq.
Earlier on Wednesday, a deadly blast on a military bus occurred in Damascus, reportedly killing 14 people.
Bombardment by the regime of President Bashar Al Assad killed 13 people in Idlib in the hours after the bus bombing.