BAGHDAD, Iraq - The United States launched new airstrikes on the Sunni insurgent stronghold of Fallujah and nearby villages today. Iraqi officials said 44 people were dead, including women and children.

In Baghdad, a suicide attacker detonated a car packed with explosives in front of a row of parked police cars, killing at least five people and wounding 20, officials said. Six police cars were blocking a bridge when a car drew up to them, said policeman Medhafar Ismail.

U.S. troops also battled insurgents in central Baghdad, an Interior Ministry official said. More than 50 suspects were detained during the sweeps on Haifa Street, a virtual "no-go" area for U.S. forces, said ministry spokesman Sabah Kadhim.

There was no immediate word on casualties.

The clashes came a day after a team of kidnappers grabbed two Americans and a Briton in a dawn raid on their home in a upscale Baghdad neighborhood.

The Fallujah attacks began late Thursday, targeting a compound about 12 miles south of Fallujah where militants loyal to Jordanian-born terror mastermind Abu Musab al-Zarqawi militants gathered to plot attacks on coalition forces, the military said in a statement.

Today, warplanes bombed a cluster of houses in Fallujah believed to be used by Zarqawi's Tawhid and Jihad group.

The U.S. military claimed that up to 60 suspected insurgents may have been killed. U.S. forces, however, have not patrolled inside Fallujah since ending a three-week siege of the city that left hundreds dead.

Health Ministry spokesman Saad al-Amili said at least 44 people were killed and 27 injured in the Fallujah strikes. He said 17 children and two women were among the wounded. Hospital officials in Fallujah said women and children were also among the dead, but exact figures were not immediately available.

Insurgents have only strengthened their grip on Fallujah since the United States withdrew, regularly mounting attacks against Marine positions and military convoys on the city's outskirts.

On Thursday, three U.S. Marines assigned to the 1st Marine Expeditionary Force were killed by hostile fire in separate incidents in the western Anbar province while conducting security operations, the military said.

Insurgents have turned to kidnappings and spectacular bombings as the weapon of choice to pressure the United States and its allies to pull out of Iraq and embarrass the interim government of Prime Minister Ayad Allawi. Even in the heavily guarded Green Zone - where the U.S. Embassy is located - foreigners were warned in the last 10 days to be on guard against possible kidnapping attempts, a U.S. official said on condition of anonymity.

The U.S. Embassy identified the Americans kidnapped Thursday as Jack Hensley and Eugene Armstrong, but the identity of the British man was not disclosed.

The three worked for Gulf Services Co., a United Arab Emirates-based construction company.

Early Friday, 40 miles north of Baghdad, police found the corpse of a man they believed to be a Westerner. The body was pulled from the Tigris River. The man, described as tall and well built with blonde hair, had been shot in the back of the head. His hands were cuffed behind his back.

It appeared unlikely that the corpse was that of one of the three Westerners kidnapped Thursday because it was found so far away from the capital.

An Internet statement and videotape released by an Iraqi militant group Thursday shows the purported firing squad-like killing of three Iraqi truck drivers who had "confessed" to carrying supplies for American forces.