Three US soldiers and three Iraqi rebels have been killed in three separate clashes.
In the latest attack, one US soldier died and two were wounded in an assault on a convoy to the east of Fallujah.
Another US convoy hit a bomb in the central Iraqi town of Baquba, killing one soldier and injuring two others.
Earlier, the US military announced that one of its soldiers and three Iraqi insurgents died in a gun battle in Taji, north of Baghdad.
The shooting came after an attack on a US military convoy, according to Brigadier General Mark Kimmitt, deputy director of operations for the US army.
The military spokesman said the insurgents detonated a bomb beside the road, and then fired rocket-propelled grenades.
One other US soldier was also injured in the incident, he said.