Al Qaeda in Iraq claimed responsibility in a posting on the Internet, but the authenticity could not be verified. In February, a suicide bomber blew himself up at the same place, killing 21 people.
Elsewhere, a Shi'ite mother and seven of her children were found shot to death in their beds yesterday in Baghdad. One boy survived, police said. The distraught father, who was not at home at the time, blamed the killings on sectarian hatred.
Two suicide car bombers also killed at least seven Iraqi customs officials at the Walid border crossing into Syria, the US military said. Syrian authorities closed the crossing point, turning back about 300 Iraqis trying to return home, a Syrian source said, speaking on condition of anonymity because of the sensitive relations between the neighboring countries.
A suicide car bomber also rammed into a police convoy carrying an Iraqi brigadier general near the northern city of Mosul, killing five police officers and wounding three, the US military and police said. The senior officer was not injured.
A suicide car bomb in Kirkuk killed at least four civilians and wounded 15, police said. A second car bomb was rigged to explode as rescuers rushed to the scene, but it was found and detonated by American troops, police reported.
Two other suicide car bombers struck near Fallujah, killing an Iraqi civilian and wounding a Marine, the US Marines said.
A roadside bomb in southeastern Baghdad injured five American soldiers, the US command said. They were in stable condition at a military hospital.
Separately, Prime Minister Ibrahim al-Jaafari criticized US and multinational forces for shooting at Iraqi civilians who act suspiciously near patrols or military areas, saying such cases should be handled in a ''civilized" way, such as shooting at tires instead of passengers.
Lieutenant Colonel Steven Boylan, a spokesman for the US command, said American forces investigate all fatal shootings. He blamed the problem on the growing use of suicide car bombs as an insurgent weapon.
