WASHINGTON (TIP): In a new Islamic State video, jihadist fighters are shown flaunting the American M16 rifles that may have been seized by them from Iraqi soldiers or found in weapons caches dropped by the US.

A video released by Islamic State of Iraq and Syria‘s media arm in northern Iraq purportedly shows more than a dozen of the terror group’s fighters undergoing weapons training wielding American M16 rifles, according to Flashpoint Intelligence.

“It is noteworthy that the use of American rifles by Islamic State fighters is rare and is only seen in Iraq,” Flashpoint said in a research note, using another name for the militant group.

“These rifles were likely left by US forces or seized from Iraqi soldiers,” it said. Most jihadist fighters have been found to be using Russian AK-47 rifles and that the video’s release could suggest ISIS recently seized a cache of M16s, the NBC News reported. ISIS propaganda material in the past has shown fighters flaunting what appear to be US-made weapons, tanks and Humvees seized from retreating Iraqi forces.

The United States has supplied Iraq with hundreds of millions of dollars in military hardware — including humvees. Iraq’s government said in June that it lost 2,300 Humvees to ISIS when the militants seized the city of Mosul. Last year, an ISIS video claimed that an airdrop of weapons intended for Kurdish fighters had ended up in the militants’ hands.