A truck packed with rockets blew up on Wednesday near the home of a police general in Baghdad, killing 18 people in the deadliest single blast in the city in more than three months. Three US soldiers were killed by gunfire north of the capital.
A US military spokesman said the blast appeared to have been an accident that occurred as Shiite militiamen were transporting the weapons through a densely populated neighbourhood of northern Baghdad - possibly to fire at a nearby American base.
At first, Iraqi police said a suicide truck bomber had targeted the house of an Iraqi police general, who was not at home but whose nephew was among those killed. Police said seven people were wounded, including the general's elderly parents.
But the US military disputed the police account, saying Shiite extremists were transporting rockets and mortars on a tractor-trailer when the weapons mistakenly exploded.
Witnesses also confirmed the vehicle was carrying weapons.
"They were trying to attack us ... And it went off (accidentally)" said US military spokesman Lt Cl Stev Stove, who provided the death toll. "They wouldn't waste rockets like that" in a suicide attack.
A car bomb exploded on Thursday night in the Shiite district of Karradah in east Baghdad, killing seven people, including three policemen, and wounding 11 other people, according to police and hospital sources who spoke on condition of anonymity because they were not supposed to release the information.