The US military said today its forces killed 25 in operations targeting al-Qaeda militants near Baghdad.
A US military spokesman said US troops had engaged a "hostile force" and that three weapons caches had been found in the area containing anti-aircraft weapons and surface-to-surface missiles.
But the head of a Sunni Arab tribal group fighting alongside US forces claimed the airstrikes had killed 45 of his men while they were manning vehicle checkpoints.
Sheikh Jassem, head of the Awakening Council in Taji, just north of Baghdad, said the weapons belonged to the Islamic Army, a nationalist Sunni insurgent group that recently joined forces with the US military.
He said the US ground and air assault on his men began late on Tuesday night and lasted about 12 hours.
"The Americans in Taji are our friends. They are co-operating with us. If the attack was a mistake, we just want to know the reasons. If they attacked us deliberately, then we will decide what to do," Sheikh Jassem said.