A militant group linked to Jordanian terror suspect Abu Musab al-Zarqawi (search) claimed responsibility Sunday for a recent attack on a military headquarters in Samarra that killed five U.S. soldiers and one Iraqi National Guardsman (search).

The claim by al-Zarqawi's Tawhid and Jihad movement, which was posted on a Web site known for being a clearinghouse for such statements, claimed that dozens of Americans and hundreds of Iraqis died in Thursday's assault. The U.S. military has said insurgents detonated a car bomb and then fired mortars at the building used jointly by the 1st Infantry Division and Iraqi guardsmen.

"One of the lions of the martyrs' brigade, entered the building and destroyed it completely, plus six Hummers, including those who were inside them, thank God," the al-Zarqawi group said in its statement.

As soldiers tried to escape from the building, "the soldiers of God were waiting for them and rained those who came with mortar shells," the statement said.

The accuracy of the group's account could not be verified.

Iraq has been torn by a persistent insurgency since the fall of Saddam Hussein more than 14 months ago.

On Saturday, U.S. Marines clashed with guerrillas taking cover at a taxi stand in a stronghold of support for Saddam's ousted regime, killing three people and wounding five, military and hospital officials said.

Insurgents clad in black attacked the Marines in the city of Ramadi (search), a hotbed of anti-coalition sentiment. U.S. forces returned fire, blasting the stand into a twisted pile of molten metal. Blood pooled on the asphalt. At least one child was wounded in the crossfire.

The deaths came the same day four U.S. Marines died in a vehicle accident while conducting security operations in an area of western Iraq, the U.S. command said Sunday.

The Marines were killed in Anbar, a Sunni-dominated area west of the Iraqi capital that includes Ramadi, Fallujah and Qaim on the Syrian border. They were assigned to the 1st Marine Expeditionary Force.

North of the capital, insurgents blew up three liquor stores in Baqouba on Saturday, prompting concern that Islamic militants may be trying to impose their strict interpretation of Islam there, witnesses said. The blasts killed a passing taxi driver, said Dr. Nassir Jawad from Baqouba General Hospital.

Also in Baqouba, insurgents detonated two roadside bombs Saturday as a U.S. patrols passed. Two soldiers and one civilian were wounded in the two incidents. All were evacuated to a combat hospital.