Airliners attacked tonight (light for Thursday) the base of American forces in Tanaf, in the border triangle between Syria, Jordan and Iraq.
A senior U.S. military official told the Associated Press that it was a combined and coordinated attack by several aircraft against the base, but claimed there were no U.S. casualties in the attack.
According to the source, who provided the information anonymously, no casualties are also known to local forces and allies of the United States in the attack.
The main suspects in the attack are pro-Iranian militias active in Syria.
In the past, Iranian UAVs have attacked US bases in Iraq and Syria.
Last month, U.S. fighter jets intercepted unidentified UAVs over a U.S. base in Syrian territory.