The commander of a powerful Libyan militia said Monday that looters had stolen “a large number” of shoulder-fired, heat-seeking missiles from the militia’s base when protesters who called for dismantling the country’s militias overran the compound.

Ismail Salabi, the commander of Rafallah al-Sahati, a powerful Islamist militia in Benghazi, said in an interview that the missiles, used by fighters to “hit airplanes” and known to the U.S. intelligence community as MANPADS (man-portable air-defense systems), were stolen along with 2,000 semiautomatic rifles and ammunition, as the militia withdrew from its base amid a firefight early Saturday.