Terrorist fighter pilots: Fears Isis has an airforce

A MiG-21 used by the Syrian air force in 2012. The Syrian Observatory for Human Rights claims Isis has obtained three such war planes. Photo / Supplied

Islamic State (Isis) militants are believed to be learning to fly three captured fighter jets, which could signal the terrorist group taking to the air for the first time.

Monitoring group the Syrian Observatory for Human Rights claims the militants have obtained three war planes, believed to be MiG-21 and MiG-23 supersonic fighter jets, and have been flying them from the Al Jarrah airbase in Aleppo, Syria.

The UK-based monitoring group said witnesses who live close to the airbase have seen a warplane taking off and flying at a low altitude over the area. The sources claim Isis (also known as Islamic State) militants seized the aircraft when it took control of military airports in Syria's Aleppo and Raqqa provinces.

Rami Abdul Rahman, the monitoring group's founder, claims former Iraqi officers who served under Saddam Hussein have been training the Iraqi militants to fly the aircraft, the BBC reported.

"People saw the flights, they went up many times from the airport and they are flying in the skies outside the airport and coming back," Mr Rahman said.

But the US military has said it is "not aware" of Isis conducting any flight operations in the area.

"We're not aware of Isis conducting any flight operations in Syria or elsewhere," Central Command spokesman Colonel Patrick Ryder said.

"We continue to keep a close eye on Isis activity in Syria and Iraq and will continue to conduct strikes against their equipment, facilities, fighters and centres of gravity, wherever they may be," he added.

Pro-Isis Twitter accounts have previously posted pictures of captured military aircraft in Syria, but analysts and diplomats said at the time they appeared unusable.

Additional reporting by Reuters