Two of the Multi-National Division - Baghdad soldiers died when the bomb struck their vehicle during a patrol, according to a statement. The third died later of wounds suffered in the attack, the military said.
The statement did not provide more details about the location. The soldiers' identities were not released because relatives had not yet been notified.
The latest deaths brought to 3,996 the number of U.S. service members and Pentagon civilians who have died since the war began on March 20, 2003, according to an Associated Press count. Rocket or mortar fire killed one U.S. soldier and wounded four others Friday south of Baghdad, the military said.
Meanwhile, a U.S. attack helicopter fired on two checkpoints manned by U.S.-allied Sunni fighters near Samarra, 60 miles north of Baghdad, killing six and injuring two, Iraqi police said.
The U.S. military said an AH-64 Apache helicopter fired on the positions after five people were "spotted conducting suspicious terrorist activity" in an area notorious for roadside bombs.
"Initial reports suggested the attack may have been a Sons of Iraq checkpoint," the military said, using a term for the armed U.S.-backed groups. "The incident is currently under a joint Iraqi-Coalition Force investigation."
A police officer, speaking on condition of anonymity because he wasn't authorized to release the information, said the six members of the so-called awakening council were killed and two others were wounded when an air strike hit two checkpoints about 100 yards apart.
The air strikes came some two hours after U.S. soldiers stopped at the two checkpoints to meet with the Sunni fighters, according to a local leader for the so-called awakening council.
"They asked us general questions like: have you gotten your IDs and do you need anything and then they left," Sabbar al-Bazi told The Associated Press. "Two hours later, after I had gone home, I heard two explosions, probably caused by two missiles, and machine-gun fire from a helicopter."
Lt. Col. Dhiya Mahmoud Ahmed, an Iraqi military officer in charge of security in the area, said he told the Americans after the attack that he had been aware of the friendly checkpoints for two days.
AP Television News footage of the aftermath showed awakening council members loading bodies into a pickup. Their faces were masked and they wore bright yellow vests - apparently to identify themselves for U.S. forces as members of friendly groups. Bloodstained rocks and bits of flesh could be seen around the checkpoint.
U.S.-funded awakening councils, which first sprung up in Anbar province west of Baghdad and spread to Baghdad and surrounding areas, are composed of ex-Sunni insurgents who turned against al Qaeda in Iraq and joined forces with the Americans.
But the Shiite-dominated leadership in Baghdad has been ambivalent toward the mostly Sunni councils, fearing they could turn against the government as America draws down its forces.
The U.S. command credits those groups, a cease-fire by anti-American Shiite cleric Muqtada al-Sadr's Mahdi Army militia and the addition of an extra 30,000 American troops with a drastic drop in violence nationwide.
However, as told in this video produced by GuardianFilms for Britain's Channel 4, thousands of Iraqis employed at $10 a day by the U.S. to take on insurgents as part of awakening councils are going on strike because they haven't been paid.
Sunni men in Diyala province said they have been used by the Americans "to do their dirty work" in battling al Qaeda in Iraq fighters, for which American and Iraqi politicians have claimed political success.
The men, who say they are excluded from jobs in the police and army by the Shia government, feel abandoned by the U.S. and showed their discontent by staging a strike.
Comments from dozens of awakening councils across the country showed that a majority had not been paid, and are considering a nationwide, coordinated strike.
U.S. Army Captain Robert Gable told the filmmakers, "If they quit, then it appears that the public is quitting with them, and then it's all reliant on the government of Iraq to provide security. That is something that we hope does not happen."
Al Sadr Followers In Power Struggle
Tensions between rival Shiite militia factions loosely associated with al-Sadr's movement have been on the rise amid a violent struggle for power in the oil-rich south.
U.S. officials have been careful to avoid accusing the young cleric of any role in recent fighting but have cracked down on his followers in volatile cities south of Baghdad and in the capital itself.
The U.S. military officials also said insurgents had used mortars to attack a military outpost in Hillah, about 60 miles south of Baghdad, on Saturday but no casualties were reported.
On Friday, U.S. and Iraqi troops clashed with Shiite gunmen in southwestern Baghdad.
The U.S. command said American helicopters fired a Hellfire missile and a 30 mm cannon at gunmen who had attacked troops with mortars or rockets. Six of the gunmen were killed and three others detained, the military said.
Al-Sadr proclaimed a cease-fire last August and extended it indefinitely last month. But Al-Sadr's supporters have complained the Shiite-led government has used the cease-fire to accelerate a crackdown against their movement in the capital and the Shiite heartland to the south.
The firebrand cleric, who led two uprisings against U.S.-led forces in 2004, has authorized his followers to defend themselves if attacked.
In Other Developments
- A bomb exploded on a minibus in a predominantly Shiite area in eastern Baghdad, killing at least 1 passenger and wounding eight others, including a woman, police said.
- A roadside bomb targeting a police patrol also killed one passer-by and wounded seven other people, including five officers, in the northern city of Kirkuk, according to police Col. Burhan Tayyeb.
- Late Saturday, bombs exploded at four offices of the Iraqi Red Crescent Society in the Mansour district of Baghdad, causing damage but no casualties. The Red Crescent Society is the Muslim world's equivalent of the Red Cross.
- A roadside bomb targeting a police patrol also killed one passer-by and injured seven, including five officers, in the northern city of Kirkuk, police said.
- An awakening council member in western Baghdad's Mansour neighborhood was killed and four others were injured in a mortar blast, police and hospital officials said.