Baghdad, Iraq ? A U.S. contractor was kidnapped Monday in the Baghdad area, the latest in a string of abductions that have forced many foreigners to work here under armed guard. A pickup truck also exploded near a U.S. convoy as it patrolled a crowded market in the troubled city of Samarra, killing at least three people and injuring more than 20 others.

Three suicide bombers also hit a Marine outpost in western Iraq, wounding three Marines and three civilians in an attack claimed by Iraq’s most feared terror groups.

A U.S. Embassy spokesman said the American contractor, who was working on a reconstruction project, had been abducted around noon. He refused to release an identity or other details, but said the contractor’s family had been informed.

In Samarra, a troubled city 60 miles north of Baghdad, a pickup truck blew up near a U.S. patrol, killing three civilians and wounding more than 20 others, including four U.S. soldiers, officials said. One soldier was evacuated for medical treatment, and the others were treated and returned to duty, the U.S. military said.

Loudspeakers urged residents to donate blood as the wounded poured into the hospital. Most of the injured were women and children, hospital official Abdul Nasir Hamid said. The incident was in the Sunni Triangle, a stronghold of the insurgency.

Early Monday, suicide bombers tried to crash two cars and a fire truck into Camp Gannon in the western desert, but “the drivers of the vehicles were stopped short of the camp by forces manning the checkpoints,” a U.S. military statement said.

The vehicles exploded, wounding three Marines and three civilians and causing slight damage to the concrete barriers and a nearby mosque, U.S. officials said.

Insurgents also fired at the camp, which is in the town of Qaim near the Syrian border, and a U.S. attack helicopter destroyed a car carrying a gunman, officials said.

The attacks came nine days after dozens of heavily armed insurgents tried unsuccessfully to break into Abu Ghraib prison outside Baghdad. That battle wounded more than 40 U.S. soldiers and a dozen prisoners at a facility synonymous with the U.S. military’s prison abuse scandal.