BAGHDAD — 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 them commandos sent to the area as part of a U.S.-backed military crackdown.

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

The U.S. military had said those killed included 14 national policemen and eight members of a Sunni group allied with the Americans to fight against al-Qaida in Iraq. The military later 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.

The rural territory around Diyala's provincial capital of Baqouba has been one of the hardest areas to control despite numerous U.S.-Iraqi military operations aimed at routing insurgents from their safe havens 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. The death toll from the outbreak stood at five, it said.

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.

The United Nations stressed Thursday that the current outbreak appeared less severe than one that occurred last year.

The World Health Organization has confirmed 306 cases so far this year, well below the 4,700 reported in 2007, according to a statement. It said Iraq has an average of 600 cholera cases reported each year.

U.N. officials who recently discussed the issue with government and health officials in Babil province also praised the government response, saying hospitals were prepared and an information drive was under way.

On Wednesday, a suicide bomber killed a U.S. soldier in Diyala, the military said 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.