Numerous versions of this nine-second clip have been circulating on the Internet since Saturday, feeding speculation that militants with the Islamic State have managed a lofty accomplishment: learning to fly fighter jets they captured in Syria.

The video appears to depict a fighter flying somewhere over the Middle East. It has circulated on social media accounts like this one that distribute propaganda from the Islamic State.

The video’s release follows reports from the Syrian Observatory for Human Rights, a Britain-based group tracking the war, that Iraqi pilots have defected from Baghdad’s military and are teaching militants how to fly. Three jets have been seen flying from the captured al-Jarrah airfield east of Aleppo, the group said.

It’s a significant claim. While it has been clear for some time that the Islamic State had captured airfields in Syria that were home to government-owned fighter jets, neither flying them nor maintaining them is easy. And it isn’t clear when the video was recorded, or who is flying the jet.

Gen. Lloyd Austin, commander of U.S. Central Command, told reporters at the Pentagon on Friday that the U.S. military does not have any operational reporting indicating the Islamic State is flying jets, and could not confirm that it does.

“And to the degree that pilots may have defected and joined the ranks of ISIL, I don’t have any information on that either,” he said, using one of the acronyms for the group.

The militants have previously release both photographs and video of some of the jets they’ve captured. This one shows Syrian fighter jets kept in a hangar: