The series of car bomb blasts, which killed at least seven civilians, touched all corners of Baghdad. But they did little to disrupt a wide-ranging security sweep seeking to weaken militia groups' ability to fight U.S.-allied forces — and each other.
The attacks, however, pointed to the critical struggle to gain the upper hand on Baghdad's streets. The Pentagon hopes its current campaign of arrests and arms seizures will convince average Iraqis that militiamen are losing ground.
Most of the latest resistance has come from Sunni factions, which perceive their Saddam Hussein-era influence slipping away as the majority Shiites extend their political muscle and bolster ties to Iran.
In Baghdad's Dora neighborhood — a longtime Sunni militant hotbed — two parked cars wired with explosives were triggered as a joint U.S.-Iraqi patrol rolled pass. The convoy was unharmed, but the blast killed at least four civilians and injured 15.
Control of the Dora district, a once-upscale neighborhood favored by Saddam's regime favorites, is important as a gateway between Baghdad and the Iraq's Shiite-dominated south. Two other car bomb blasts came as security forces moved through the city, killing at least three civilians.
Outside Baghdad, troops also faced Sunni ambushes. In Buhriz, about 30 miles northeast of Baghdad, Sunni gunmen and soldiers from the 1st Squadron, 12th Cavalry Regiment engaged in a 20-minute firefight.
U.S. Bradley fighting vehicles fired 25mm rounds into homes shielding the gunmen, said an Associated Press reporter traveling with the unit. No U.S. casualties were reported and the militant toll was not known.
In other developments:
A top adviser to Iraq's prime minister, Sami al-Askari, said al-Sadr traveled to Iran "a few days ago," but gave no further details on how long he would stay. He denied that al-Sadr left the country in fear of arrest under the security crackdown. But a lawmaker loyal to al-Sadr, Saleh al-Ukaili, insisted that al-Sadr is in Iraq and claimed the accounts of his departure were part of a "campaign by the U.S. military" to track down the elusive cleric.
A statement from the office of Iraqi President Jalal Talabani quoted him saying that he has no information on al-Sadr's location, but he believed "many of the Mahdi Army commanders have been instructed to leave Iraq to facilitate the mission of the security forces."