BAGHDAD - Two suicide car bombers struck checkpoints at Baghdad bridges within minutes of each other yesterday, killing at least 23 people and damaging the spans despite increased U.S. efforts to target the insurgent networks planning deadly vehicle attacks.

The U.S. military announced earlier yesterday that it had conducted a series of raids against car-bombing networks across the country, killing four suspected insurgents and detaining nine.

U.S.-led forces have focused on disrupting car-bomb-making factories after several high-profile attacks that have killed hundreds in Baghdad and surrounding areas in recent weeks.

Officials say al-Qaeda-linked Sunni insurgents have been trying to provoke retaliatory violence from mainly Shiite militias that have agreed to lie low to avoid confrontations with Americans during a 12-week-old security crackdown.

The twin attacks began about 6 p.m., when the driver of a sedan waiting in a line of cars outside a police checkpoint near the old Diyala Bridge blew up his vehicle, partly collapsing the span, police said.

About two minutes later, the driver of a large fuel truck barreled toward a second checkpoint at the nearby new Diyala Bridge and blew up his vehicle, police said. The bridge was damaged, and firefighters worked to extinguish burning cars that had been driving across during the attack.

The bombings at the bridges, which cross the Diyala River, a Tigris tributary, killed 23 people - 11 police and 12 civilians - and wounded 57, police said.

Baghdad's bridges repeatedly have been targeted by bombers. The most serious previous attack occurred April 12 when a suicide truck bomb collapsed the steel-girder Sarafiyah bridge, plunging cars into the water and killing 11 people. Two days later, a suicide car bomb killed 10 people at the Jadriyah bridge.

The blasts yesterday occurred despite a series of measures aimed at reducing violence in the capital.

U.S. and Iraqi security forces have increased the number of checkpoints in the capital and banned large trucks from crossing without strict searches. They also have long imposed a four-hour weekly driving ban during Friday prayers in Baghdad, but that ban ended on schedule three hours before the attacks.

The U.S. commander in northern Iraq, Maj. Gen. Benjamin R. Mixon, meanwhile, said he did not have enough troops for the mission in Diyala, a province northeast of Baghdad that has seen a rise in violence attributed largely to insurgents who fled the Baghdad security operation.

Mixon also said Iraqi government officials were not moving fast enough to provide the "most powerful weapon" against insurgents - an administration that worked and supplied services for the people.

Mixon already has received extra troops and has increased attacks on insurgents, but he has asked Lt. Gen. Raymond Odierno, the No. 2 commander in Iraq, for more.

"I laid out a plan for Gen. Odierno on the numbers of forces that I would need," Mixon told Pentagon reporters by video conference from Iraq. "We have made progress.. . . We have taken terrain back from the enemy. Gen. Odierno intends to give me additional forces as they become available."

2 U.S. Troops Killed

Two U.S. soldiers were killed in separate bombing attacks, the military announced yesterday.

One soldier from the Multinational Division-

North was killed Thursday in an explosion in

Diyala province, northeast of Baghdad.

The second soldier was killed in eastern Baghdad when a bomb exploded near his patrol.

The deaths raised to at least 3,385 the number of U.S. military personnel who have died since the Iraq war started in March 2003, according to an Associated Press count.

- Associated PressEndText