Gunmen ambushed Iraqi forces raiding a Sunni village northeast of Baghdad on Wednesday, killing 22 policemen and U.S.-allied fighters, U.S. and Iraqi officials said.

The attackers in the insurgent stronghold of Othmaniyah apparently had been tipped off about the raid and were waiting for the Iraqi forces to arrive, officials said.

The U.S. military said 14 national policemen and eight members of a Sunni group that has joined forces with the Americans against Al Qaeda in Iraq had been killed.

Initial reports indicated they came under fire from rocket-propelled grenades and Russian-made machine guns, the military said in an e-mailed statement.

Clashes broke out in the village, south of the Diyala provincial capital of Baqouba, shortly after 11 a.m. and lasted about two hours, according to police and government officials.

Amir Rafat, a member of the Diyala provincial council, blamed Al Qaeda in Iraq for the attack and said it appears the insurgents had advance information about the raid because the ambush was carefully planned.

The attackers also suffered casualties, Rafat said, but he gave no numbers.

The joint Iraqi forces were struck by a roadside bomb followed by a hail of gunfire as they entered the village to search for wanted insurgents and weapons, a police officer in Baqouba said, speaking on condition of anonymity because he wasn't authorized to release the information. He gave a slightly lower death toll of 12 policemen and eight awakening council members.

The rural territory around Baqouba has been one of the hardest areas to control despite numerous U.S.-Iraqi military operations aimed at routing insurgents from their safehavens there.