According to Kurdish activists and arms researchers, Turkish versions of the U.S. M72 LAW anti-tank rocket keep popping up in ISIS stockpiles.

One such rocket was discovered and documented by Conflict Arms Research — an arms research organization dedicated to tracking weapons supplies in conflict zones through various chains of custody.

The HAR-66 — the Turkish version of the U.S. M72 — was discovered by the research group on the outskirts of Mosul in mid-March.

“Islamic State forces discarded this item during a battle against Rapid Response Division in the Al Jawsaq neighbourhood in early March 2017,” reads a report provided to Military Times.

Researchers at the arms tracking group were unable to ascertain how the anti-tank rocket ended up in ISIS custody. “I haven’t seen any in Iraqi inventories in the last three years,” said Damien Spleeters, a researcher at Conflict Arms Research.

Other HAR-66 rockets have been discovered by the People’s Protection Unit, or YPG, in Syria. Photos and videos of the captured rockets from ISIS have been documented and uploaded to the group’s official press page.