A military outpost in southern Syria was hit in a coordinated attack on Wednesday, but US officials said no American troops stationed there were injured or killed, The Associated Press reported.
Initial reports said the attack appeared to include two drone strikes and a small number of rockets.
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.
US and coalition troops are based at al-Tanf to train Syrian forces on patrols to counter Islamic State terrorists.
Officials said there was no information on whether local Syrian forces were injured or killed in the attack.