Scene of explosion in Baghdad, Wednesday

In the latest attack targeting Iraqi security forces, police in Baghdad say insurgents lured police to a house in the west of the capital and then set off hundreds of kilograms of explosives as they entered the home. Seven policemen and 22 civilians were killed in the blast, which shook the city late Tuesday.

Police at the Ghazaliyah station in west Baghdad say they received an anonymous phone call late Tuesday from a man who said he knew the location of a possible foreign fighter hideout.

A senior police officer at the station, who declined to be identified, tells VOA that he was suspicious of the call and tried to persuade his lieutenant not to raid the house until the police could collect more information.

The police officer says the lieutenant would not listen to him and left the station with nearly a dozen policemen. The officer says the men were immediately ambushed as they entered the house. He describes the raid as a huge, tragic mistake.

Iraqi woman stands outside houses destroyed in west Baghdad blast, Wednesday

The U.S. military says it believes more than 800 kilograms of explosives were used in the attack. The blast also leveled six neighboring homes, trapping residents underneath mounds of rubble.

Earlier Tuesday, insurgents, using car bombs, ambushes, and assassinations, killed 26 Iraqi security force members and wounded 43 others in the Iraqi capital and across the restive "Sunni Triangle." The most violent attack occurred near Saddam Hussein's hometown of Tikrit. Insurgents overran a local police station, slit the throats of 12 policemen inside, and then blew up the building.

The Iraqi Interim National Assembly issued a statement on Wednesday accusing Sunni Muslim extremists of carrying out the attacks in an effort to prevent the country from holding its first free elections next month.

Iraqi leaders say the attacks are designed to cause panic among the Iraqi people and to provoke an ethnic conflict with Iraq's Shiite Muslims, who form the majority in Iraq and are strong supporters of the elections.

U.S.-trained Iraqi security forces have been the target of attacks for months. Insurgents accuse them of being collaborators with the United States and with the U.S.-supported Iraqi interim government.