The U.S. military on Wednesday accused Russian mercenaries fighting on the side of eastern Libya forces of planting land mines and improvised explosive devices in and around the Libyan capital, Tripoli.

The U.S. Africa Command, or AFRICOM, said verified photographic evidence shows “indiscriminately placed booby traps and minefields” around the outskirts of Tripoli and all the way east toward the strategic coastal city of Sirte since mid-June. There was no immediate comment from Russia or the Wagner Group, a Kremlin-backed private security company that has been implicated in the conflict in the North African country.