Iraqi soldiers discovered 22 bodies in a mass grave in the Lake Tharthar area northwest of Baghdad, the U.S. military said Tuesday.

The bodies were found Saturday during a joint operation with U.S. forces, the military said in a statement.

Iraqi police last month reported finding 25 bullet-riddled bodies, some decapitated, in a mass grave in Nadhum village, close to Lake Tharthar. At the time, police said it appeared the victims had died within the past three months.

It was not immediately clear whether Saturday's discovery contained the same bodies found earlier by Iraqi police, or whether it was a second mass grave.