Multiple witnesses told Human Rights Watch that the bodies of those killed, including bodies of members of Iraqi security forces, were thrown into a naturally occurring sinkhole at a site known as Khafsa, about eight kilometers south of western Mosul. Local residents said that before pulling out of the area in mid-February, ISIS laid improvised landmines at the site, which are sometimes referred to as improvised explosive devices or booby traps.

“This mass grave is a grotesque symbol of ISIS’s cruel and depraved conduct – a crime of a monumental scale,” said Lama Fakih, deputy Middle East director at Human Rights Watch. “Laying landmines in the mass grave is clearly an attempt by ISIS to hide evidence of its crimes.”