Insurgents are now using unwitting kidnap victims as suicide bombers — seizing them, booby-trapping their cars without their knowledge, then releasing them only to blow up the vehicles by remote control, the Defense Ministry warned Thursday.

A U.S. official who spoke on condition of anonymity said he was aware of such incidents but was unable to provide further details.

The Iraqi announcement — the latest development in the deadly war waged by the insurgency — came as widespread lawlessness swept the capital Thursday with kidnappings, deadly attacks on police, the discovery of more mutilated death squad victims and a brazen daylight bank heist by men dressed as Iraqi soldiers.

It was unclear from the Defense Ministry's statement whether the insurgents are using kidnap victims because they are having trouble finding recruits for suicide missions. U.S. officials have said insurgents often tape or handcuff a suicide driver's hands to a car, or bind his foot to the accelerator pedal, to ensure that he did not back out at the last minute. The remains of such hands and feet have been found at blast sites.

Although roadside bombs are the main weapon used by insurgents, suicide car bombers are often their most effective one — designed to maximize casualties and sow fear among the population. According to the Washington-based Brookings Institution, since the fall of Saddam Hussein to Sept. 17 there have been 343 suicide car bombings involved in attacks causing multiple deaths around Iraq.

"According to our intelligence information, recent car bomb explosions targeting checkpoints and public places have nothing to do with (traditional) terrorist operations," the Defense Ministry said in its statement.

It said that first "a motorist is kidnapped with his car. They then booby-trap the car without the driver knowing. Then the kidnapped driver is released and threatened to take a certain road."

The kidnappers then follow the car and when the unwitting victim "reaches a checkpoint, a public place, or an army or police patrol, the criminal terrorists following the driver detonate the car from a distance."

The U.N. Assistance Mission in Iraq's Human Rights office warned that the number of Iraqi civilians killed in July and August hit 6,599, a record high number that is far greater than initial estimates had suggested and points to the grave sectarian crisis gripping the country.

It offered a grim assessment across a range of indicators, reporting worrying evidence of torture, unlawful detentions, the growth of sectarian militias and death squads, and a rise in "honor killings" of women.

The United Nations' chief anti-torture expert warned Thursday that torture may now be more widespread than it was under Saddam's regime, with militias, terrorist groups and government forces disregarding rules on the humane treatment of prisoners.

"What most people tell you is that the situation as far as torture is concerned now in Iraq is totally out of hand," Manfred Nowak said in Geneva.

More than a dozen apparent victims of death squads were found in the capital Thursday, many showing signs of torture.

A U.S. soldier was killed Thursday while operating in the restive Anbar province west of Baghdad, the military announced. Earlier in the day, the military said another American soldier was killed in northern Baghdad on Wednesday when a roadside bomb exploded next to the vehicle in which he was traveling.

Despite the bloodshed, coalition forces moved ahead with plans to turn security responsibilities over to Iraqi troops by the end of 2007.

Italy formally handed over the reins of the relatively quiet Dhi Qar province in the south. It was the second of Iraq's 18 provinces to be turned over to local control, and paves the way for most of Italy's 1,600 troops to return home by the end of the year — a campaign promise by new Prime Minister Romano Prodi.

The overall U.S. strategy calls for coalition forces to redeploy to larger bases and let Iraqis become responsible for their security in specific regions. The larger bases can act in a support or reserve role to Iraqi troops should they need help. No timeframe has been set for the eventual drawdown of troops from Iraq.

In the Baghdad bank robbery, an Associated Press reporter saw about 15 armed men in three pickup trucks pull up outside a branch of the Rafidain Bank in the Karrada area, a downtown commercial neighborhood.

The well-organized robbery appeared to witnesses to be a regular salary pickup. Two or three of the men entered the bank, then five people exited with bags, accompanied by a man in civilian clothes who appeared to be carrying documents. They got back into their vehicles and drove off.

No shots were heard, but police 1st Lt. Mahmoud Khayyoun said a bank manager was injured and the assailants got away with an unknown amount of cash.

Elsewhere, four employees of a government-owned company were seized by eight armed men in three cars in the commercial heart of the capital as they left work, Khayyoun said. The kidnappers left the victims' car on the spot and sped off, he said.

A group of armed men also attacked a minibus carrying employees of a cell phone company, seriously wounding five of them, police Lt. Mohammed al-Baghdadi said. The attack took place in the southern Baghdad neighborhood of Dora, one of those recently swept by Iraqi and U.S. troops in the security crackdown dubbed Operation Together Forward.

Gunmen also opened fire on a car in western Baghdad and wounded two civilians. When police arrived to evacuate the wounded they too came under fire, police Lt. Thair Mahmoud said. One policeman was killed and another wounded.

Six more policemen were killed and one more was wounded in an attack on a Baghdad police station in the Khadra neighborhood, when assailants first fired a mortar at the building and then drove up in four cars and opened fire with machine guns, police said.

Another eight civilians were killed and 20 wounded in other car bombings and mortar attacks in the capital, police said.