(UPI) — The United States struck down a pro-regime drone that fired on coalition forces in Syria, U.S. military officials said.

Coalition spokesman Col. Ryan Dillon told reporters Thursday the drone fired on patrols outside the deconfliction zone. No injuries were reported.

Though he could only confirm that the drone was in support of the Assad regime, one U.S. official told CNN that Iran made the unmanned aircraft. The official said a U.S. F-15 jet that shot down the Shahed 129 drone.

“There was no warning that was provided prior to them releasing this munition on our forces,” Dillon said of the drone’s attack during a briefing. “We did have a view of this particular drone, and we were able to quickly engage and take this threat away for any further action that they may have tried to conduct.”

The official speaking to CNN said the munition the drone dropped on coalition forces was a “dud.”

The encounter comes two days after the U.S.-led coalition to fight the Islamic State attacked forces supporting Syrian President Bashar al-Assad for the third time.

The attack Tuesday against Iranian-backed Shiite militia fighters took place near the at-Tanf Garrison on Syria’s southern border.