Iraqi police on Thursday raised the death toll in an ambush against Iraqi forces raiding a Sunni village northeast of Baghdad to 35, most of whom were police commandos sent to the area as part of a U.S.-backed military crackdown.

A suicide bomber also killed a U.S. soldier Wednesday in the volatile Diyala province, the military said in a statement issued Thursday.

At least 4,171 members of the U.S. military have died in the Iraq war since it began in March 2003, according to an Associated Press count.

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

The ambush prompted clashes lasting nearly two hours in the village, which is just south of the Diyala provincial capital of Baqouba, 35 miles northeast of Baghdad.

The U.S. military initially said those killed included 14 national policemen and eight members of a Sunni group that has joined forces with the Americans against Al Qaeda in Iraq. But the military referred questions about updates to Iraqi officials.

A police officer in the provincial military operation center said 27 policemen were killed, raising the total to 35. The officer spoke on condition of anonymity because he was not authorized to release the information.

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 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.

The national police unit that was struck had been sent to the region over the summer as part of the latest offensive.

The brazen attack occurred the same day the Iraqi parliament approved a law paving the way for the first provincial elections in four years.

The breakthrough came after lawmakers decided to postpone a decision on how to resolve a power-sharing dispute over the oil-rich city of Kirkuk, which has stoked ethnic tensions in northern Iraq.

U.S. commanders have warned that failure by the central government to make progress in promoting unity among Iraq's divided ethnic and religious parties was threatening recent security gains.

Separately, Iraq's Health Ministry reported Thursday that a total of 327 cholera cases had been confirmed in central and southern Iraq since an outbreak of the disease last month.

Ministry spokesman Ihsan Jaafar said Babil province south of Baghdad has had 200 cases while 61 others were reported in Baghdad province. The death toll from the outbreak stood at five, according to the statement.

Cholera is a gastrointestinal disease that can be spread by a lack of clean drinking water. The problem has been worsened by the poor state of Iraq's infrastructure after years of neglect and war.