(CNN)An area in eastern Syria where some US troops are based came under an "indirect fire attack" Saturday but no casualties were reported, according to a US defense official.
The attack happened near a location containing oil and gas fields known as Conoco, where US troops are deployed.
"I can confirm that there was an indirect fire attack in Conoco (Syria). At this time, initial reports are no casualties, injuries (or) structural damage," the official said.
This is one of several locations in eastern Syria where US troops operate to help local partner forces fight against ISIS. There are a total of about 900 US troops in Syria.
The US will try to determine who was responsible for Saturday's attack. President Joe Biden ordered airstrikes on Iran-backed militia groups in the Iraq-Syria border region two weeks ago.