An American contractor working on a reconstruction project was kidnapped in the Baghdad (search) area on Monday, a day of violent attacks that included three car bombs that tried to ram into a remote, western U.S. base and a pickup truck that blew up in a crowded market in Samarra.

The attacks left at least three people dead and dozens injured, including seven U.S. service members.

A U.S. Embassy (search) spokesman speaking on condition of anonymity said the American contractor was abducted around midday Monday but refused to release any other details. No group immediately claimed responsibility.

In Samarra (search), 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. 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 wounded poured into the hospital. Most of the injured were women and children, hospital official Abdul Nasir Hamid said.

Also Monday, the terror group al Qaeda in Iraq claimed to have carried out its second major attack against a U.S. base in a little over a week, saying it was responsible for suicide bombers who tried to ram two cars and a fire truck into a small Marine outpost in the town of Qaim, along Iraq's border with Syria.

The attack on a security checkpoint at Camp Gannon injured three Marines and three civilians, the U.S. military and hospital officials said.

"The drivers of the vehicles were stopped short of the camp by forces manning the checkpoints," the military said in a statement.

Military authorities said the explosions slightly damaged the camp's concrete barriers and barbed wire, as well as a nearby mosque.

Insurgents also opened fire on the camp, and a U.S. attack helicopter destroyed a car with a gunman inside, officials said. It was unclear how many insurgents and suicide bombers were killed in the assault. Three Marines were evacuated for medical treatment.

The attack came nine days after dozens of insurgents used rocket-propelled grenades, mortars and a car bomb in a failed attempt to break into the U.S. military's controversial Abu Ghraib prison west of Baghdad. The attack April 2 injured more than 40 U.S. service members and more than a dozen prisoners at a facility that has become synonymous with the military's prison abuse scandal.

Al Qaeda in Iraq also claimed to have carried out that attack, although none of their statements can be independently confirmed.

Also Monday, hundreds of U.S. and Iraqi forces launched their biggest Baghdad raid in recent weeks, moving on foot through a central neighborhood and rounding up dozens of suspected insurgents, the military said.

About 500 members of Iraq's police and army swept through buildings in the Rashid neighborhood along with some 200 American soldiers, detaining 65 suspected militants, Lt. Col. Clifford Kent of the U.S. Army's 3rd Infantry Division said.

One Iraqi soldier suffered injuries but no American casualties were reported in the largest joint U.S.-Iraqi raid in Iraq's capital since the Fort Stewart, Georgia,-based 3rd Infantry Division assumed responsibility for the city on Feb. 27, Kent said.

One suspected insurgent was also being treated for wounds, the military said in a statement.

In a small victory against the wave of kidnappings, a Defense Ministry official said Monday that Iraqi security forces arrested a person who claimed responsibility for the kidnapping of two French journalists abducted and later released in Iraq.

Iraqi army soldiers detained Amer Hussein Sheikhan in the Mahmoudiya area on April 4, the official said on customary condition of anonymity. No other details were available.

Journalists Christian Chesnot and Georges Malbrunot were released in December after four months in captivity.

At the same time, a group claiming to have kidnapped a Pakistani official in Iraq has demanded money for his release, a senior Pakistani government official said without giving his name. Malik Mohammed Javed, a deputy counselor at the Pakistani mission in Baghdad, went missing late Saturday after leaving home for prayers at a nearby mosque.

Legislators met Monday to discuss rules and regulations governing their sessions, but little headway was made on forming a new government. Shiite Ibrahim al-Jaafari was named last week to the country's interim prime minister post, but he is still forming his Cabinet.

Hussein al-Sadr, a lawmaker from the coalition of outgoing Prime Minister Ayad Allawi, said his group had decided to participate in the government, adding that the inclusion must be a "real and effective one and not a nominal one."

He said the coalition was demanding four ministerial posts, including one of the main ministries.

"If our demands are not met, then we will lead the opposition in the parliament," he said.

Ali al-Dabagh, a lawmaker from the Shiite-led United Iraq Alliance, said he thought the demands were too high.

Reaching out to the country's top religious officials, one of Iraq's two vice presidents — Ghazi al-Yawer, a Sunni Arab — met with Grand Ayatollah Ali al-Sistani, a leading Shiite leader who called on voters to cast ballots during the country's historic Jan. 30 elections.

"We came as a delegation to thank Mr. al-Sistani for his great work and insistence that led to the success of the elections and formation of a National Assembly," al-Yawer told reporters after the 90-minute meeting in the holy city of Najaf.

Some have feared al-Sistani would influence the formation of a new government, signaling an increased role for the religious leadership. Al-Sistani has said he does not intend to involve himself in any political process, except for expressing his opinion during crises.

On Sunday, al-Yawer met with the influential Association of Muslim Scholars, a Sunni group with alleged ties to the insurgency. They discussed progress in naming the new government.