BAGHDAD, Iraq — A suicide bomber trailed by five cars loaded with armed insurgents slammed into a wall outside the home of an Iraqi special-forces police officer yesterday in the Sunni triangle city of Samarra, killing at least nine people on the street, officials said. Local police said the officer targeted in the attack was unhurt.

In another attack in the same region, insurgents rounded up eight police at a checkpoint outside the western city of Ramadi, then marched them into their office and shot them to death, police said yesterday. The attack was on Friday.

The U.S. military also confirmed the deaths of two more Marines in Thursday's ambush in Fallujah. That brought the death toll from the suicide car bomb and ensuing small-arms fire to at least four Marines. One of the victims was identified as Regina Clark, 43, of Centralia, Wash.

The lethal ambush on a convoy carrying female U.S. troops in Fallujah underscored the difficulties of keeping women away from the front lines in a war where such boundaries are far from clear-cut.

The suicide bombing in Samarra targeted the home of Lt. Muthana al-Shaker, said police Lt. Qassim Mohammed. Two insurgents also died when a roadside bomb they were planting outside al-Shaker's house after the attack blew up, he said.

Elsewhere, three mortar rounds struck a crowded cafe in a predominantly Shiite neighborhood in western Baghdad last night, killing five civilians and wounding seven more, police said.

Gunmen also killed two policemen from a commando unit patrolling western Baghdad yesterday, police 1st Lt. Thaer Mahmoud said. In addition, Iraqi police found the body of a slain uniformed policeman in another section of Baghdad.

In a separate incident yesterday, gunmen killed three policemen on a road about 46 miles south of Amarah, police 1st Lt. Hussein Karim Hassan said.

But it was the Fallujah ambush that may prove the most troubling for the military.

The ambush suggested Iraqi insurgents may have regained a foothold in Fallujah, which has been occupied by U.S. and Iraqi forces since they regained control of the city seven months ago.

The women in the convoy were part of a team of Marines assigned to various checkpoints around Fallujah. The Marines use females at the checkpoints to search Muslim women "in order to be respectful of Iraqi cultural sensitivities," a military statement said.

The group al-Qaida in Iraq claimed it carried out the ambush.

Thirty-six female troops have died since the war began, most of them from hostile fire. More than 11,000 women are serving in Iraq, part of 138,000 U.S. troops in the country, said Staff Sgt. Don Dees, a U.S. military spokesman.

Fallujah is a former insurgent stronghold invaded by U.S. forces at great cost in November. It also is the city where an Iraqi mob hung the mutilated bodies of two U.S. contractors from a bridge.

In Kirkuk, the northern oil city, a police spokesman said U.S. troops mounted a raid yesterday that captured the father-in-law of Izzat Ibrahim al-Douri, a former vice president to Saddam Hussein who has been described as one of the leaders of the insurgency, The New York Times reported.

Al-Douri is the last of Saddam's innermost circle of advisers still at large, and the arrest of Sufian al-Nuaimi, his father-in-law, was considered a potentially important breakthrough in the hunt for him, according to the police.