Officials said it was not clear when the victims, mostly men and boys, were shot.
The discovery was made at a time of heightened tensions in Iraq. A series of reprisal attacks following the bombing of a Shi'ite shrine on 22 February has so far resulted in the deaths of at least 200 people. A nighttime curfew remains in force in Baghdad and in other areas.
Meanwhile, police in the northern Iraqi city of Tikrit say a bomb attack has damaged a small mosque in which Saddam Hussein's father is buried. There were no reports of injuries.
(Reuters, AP)