Islamic State militants in Iraq have begun using remotely piloted aircraft, U.S. officials said.

In what may be the first report of a drone operated by the extremists, U.S. military officials said an airstrike on March 17 destroyed a small unmanned aerial vehicle in the area around Fallujah.

"We observed it flying for approximately 20 minutes. We observed it land. We observed the enemy place it in the trunk of a car and we struck the car," Army Col. Steve Warren, a Pentagon spokesman, said Thursday.

Warren described the aircraft as a "model airplane" and a "very unsophisticated piece of equipment."

"It was a commercially available, remotely piloted aircraft, really something anyone can get."

It is unclear whether the drone was providing real-time surveillance video.

"Difficult to tell exactly what they were using the drone for in this case," Warren said.

The drone was among the latest of the 5,314 Islamic State targets hit by airstrikes from U.S. and allied aircraft, he said.