Iraq's interim prime minister says negligence by some parts of the U.S.-led force in Iraq led to Saturday's massacre of 49 unarmed Iraqi National Guard recruits.
Iyad Allawi did not go into detail. But he said the Iraqi Defense Ministry is investigating the attack, responsibility for which was claimed by Abu Musab al-Zarqawi's terror group.
U.S. defense officials say the terrorists behind the massacre must be held fully accountable.
Other U.S. officials in Iraq also raised the possibility that the attack could have been an inside job or launched on information gained by terrorists who infiltrated the Iraqi recruits.
Meanwhile, a militant group, the Army of Ansar al-Sunna, has posted pictures on its website it says are of 11 Iraqi National Guardsmen it holds hostage.