BAGHDAD, Iraq - A suicide car bomber killed at least six people yesterday when he slammed his vehicle into the wall outside an Iraqi police officer's home in Samarra, an insurgent stronghold 60 miles north of Baghdad.
Local police said the officer targeted in the attack had survived, but at least four civilians on the street and two insurgents, besides the suicide bomber, had been killed.
The Samarra attack, on a day that was otherwise notable for a relatively low level of insurgent attacks, demonstrated the increasing complexity that American commanders say they have identified in insurgent tactics in recent months.
According to the police account, the suicide bomber was accompanied by several other cars carrying insurgents, two of whom were killed when a bomb exploded while they were trying to plant it on the road outside the target house after the initial attack.
The attack in Samarra showed another feature of the insurgency in its intended victim, Lt. Muthana al-Shaker, who was identified by the Samarra police as an officer of a special operations unit.
Units of that kind have been a focus of the $11 billion American-led program to train and equip new Iraqi security forces.
With the disappointments the program has encountered in raising Iraqi main force units to combat capability, special forces in the Iraqi police and army have played an important role in the successes the Iraqi forces have had.
The insurgents' reliance on suicide car bombings, including dozens of attacks across Iraq in the past month, has become the dominant feature of the war, prompting American commanders to describe the tactic as the rebels' "precision-guided weapon."
In one of the most devastating uses of the tactic against American troops, a suicide car bomber in Fallujah rammed an armored truck carrying about 20 U.S. troops on Thursday.
Most of them were female Marines, killing at least four of the women and two servicemen who were also aboard the truck.
A Defense Department statement named one of the dead servicewomen yesterday as Lance Cpl. Holly A. Charette, 21, from Cranston, R.I., and said she had been assigned to the headquarters battalion of the 2nd Marine Division at Camp Fallujah, about five miles from the city.
A separate Defense Department statement said another Marine, Cpl. Carlos Pineda, 23, from Los Angeles, died Friday from wounds sustained from insurgent small-arms fire "while conducting combat operations" in Fallujah.
The statement did not say whether Pineda was caught up in the Thursday suicide bombing, which witnesses said included insurgent fire directed at survivors after the explosion.
Marine spokesmen in Iraq released no further details yesterday about the Thursday attack, which also wounded 13 Marines, 11 of them women.
With a total of 15 servicewomen dead and wounded, the attack was by far the costliest, in casualties, of any involving women in uniform in the Iraq war, and had few precedents in scale in American combat history.
Marine officers said Friday that they were investigating whether the insurgents had detected a pattern in the movement of female Marines to checkpoint duties around Fallujah, and had deliberately targeted the truck that was rammed Thursday to inflict casualties on women.
The Marines' initial statement on the attack Friday said the victims of the bombing had been returning to Camp Fallujah from checkpoint duties when they were hit, and noted the reason for the large number of female Marines aboard the truck.
"They search female Iraqi citizens moving through the checkpoints," it said. "Female Marines are employed in this role in order to be respectful of Iraqi cultural sensitivities."
In Kirkuk, the northern oil city, a police spokesman said American troops mounted a raid on yesterday that captured the father-in-law of Izzat Ibrahim al-Duri, a former vice president to Saddam Hussein who has been described by American commanders as one of the leaders of the insurgency.
Al-Duri, the king of clubs on the "pack of cards" issued by American forces two years ago identifying the 55 most-wanted leaders of the toppled government, is the last of Hussein'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.
In other violence, two mortar shells struck a crowded cafe in the predominantly Shiite district of Shuala on Baghdad's northwestern edge at mid-evening on yesterday, killing five people and injuring six others, according to an Interior Ministry official.
Three nearly simultaneous car bombs exploded less than a half-mile apart in the district Wednesday, killing at least 18 people and injuring 46 others.
An Interior Ministry official said the body of a member of the municipal council in Sadr City, the impoverished Shiite district on the northeastern outskirts of Baghdad, was found yesterday, a day after he was abducted.
The victim, Fadhel Oda Lueibi, died from multiple gunshot wounds, the official said.