Awakening council members, a Sunni group fighting al-Qaida, inspect the site where six of their comrades were killed in a US airstrike near Samarra, Iraq, 22 Mar. 2008

Iraqi police and a local tribal leader say six members of a U.S.-backed neighborhood patrol group have been killed in a U.S. air strike on their checkpoint.

Tribal leader Abu Faruq says those killed in Saturday's attack near the central Iraqi city of Samarra belonged to his patrol group.  He says all of them were in uniform at the time.

However, the U.S. military says it carried out the air strike after five people were spotted conducting "suspicious terrorist activity" in an area known for roadside bomb attacks.  The military has denied the site was a checkpoint manned by members of Awakening Councils.

U.S.-funded Awakening Councils consist mostly of Sunni fighters who have turned against al-Qaida in Iraq and joined forces with Americans.

The groups have been a key factor in the drop in violence in Iraq in recent months.

Earlier Saturday, the U.S. military said three soldiers were killed in a roadside bomb attack Friday, northwest of Baghdad.  The military said two Iraqi civilians were also killed in the blast.

Also Friday, a U.S. soldier was killed and four others wounded by what the U.S. military called "indirect fire," a term usually used to describe rocket or mortar fire.