A rocket attack targeting the US military's Green Village base in northeast Syria failed to hit US or coalition forces, or any equipment, the US Central Command said.
What do we know about the strike?
Three 107 mm rockets targeted the base on Sunday and a fourth rocket along with rocket tubes was found at the launch point, about 5 kilometers (3 miles) away, the command said in a statement.
The Green Village base was targeted last month in violence between the US military and Iran-backed militants leaving at least one US military service member in Syria with a minor injury.
The incident triggered a US response that killed two or three militants conducting the attacks.
The Central Command said it was investigating the latest failed attack, which struck at approximately 7:05 p.m local time in Syria (16:05 GMT).
It gave no further details.
What was the US doing in Syria?
US forces first deployed in Syria during the Obama administration's campaign against Islamic State, partnering with a Kurdish-led group called the Syrian Democratic Forces. There are about 900 US troops in Syria, most of them in the east.