BAGHDAD - The US military faced complaints yesterday from its Sunni allies over allegations that more civilians had been killed by American forces, amplifying tensions as the Pentagon tries to calm anger over an airstrike last week that killed innocent people.
The disputes have further strained ties with anti-Al Qaeda fighters considered crucial in turning the tide against extremist violence.
The latest deaths occurred when US soldiers, acting on tips, stormed a mud-brick house in the village of Adwar, 10 miles south of Saddam Hussein's hometown of Tikrit. The predominantly Sunni area is home to many former members of Hussein's regime, and has been the frequent site of American raids.
The US military said a gunbattle broke out after the troops came under small-arms fire by two suspected terrorists. It acknowledged a woman was killed and a child was wounded, but said it was not clear who shot them.
Two other men were killed and the military described them as insurgents.
But Iraqi police, relatives, and neighbors said a couple and their 19-year-old son were shot to death in their beds. Iraqi police also said two girls were wounded and one later died. AP Television News video showed the doors pockmarked with bullet holes and pillows and other bedding on the floor and soaked with blood.
It was the second time in as many days that the US military conceded involvement in the death of Iraqi civilians.
On Monday, the military said it had accidentally killed nine Iraqi civilians, including a child, in an airstrike Saturday targeting Al Qaeda in Iraq south of Baghdad.
The killings illustrate the increasing difficulty in identifying the enemy as the nature of the US-led war in Iraq has changed. Many former insurgents and tribal leaders have joined forces with the Americans against Al Qaeda in Iraq.
The mistaken shootings also threaten to jeopardize the fragile relationship between the Americans and their new Sunni partners.
"Such acts by US soldiers cannot be justified and they will create mistrust and arouse suspicions between US Army and members of the awakening councils," said Abu Muthanna, a leader of a US-backed anti-Al Qaeda group in the northern Baghdad neighborhood of Azamiyah. "This could hurt the level of cooperation between the two sides."
Both US raids on Saturday and Tuesday were based on what the military said was intelligence gleaned from informants. That raised the possibility that the military was misled into targeting the households, perhaps as part of an insurgent campaign to derail the US-backed Sunni revolt against Al Qaeda in Iraq.
In yesterday's event, the US military said it "regrets the loss of an innocent civilian and the wounding of a child." It said US soldiers killed the two men in self-defense.
But the head of Adwar's Awakening Council, Colonel Mutasim Ahmed, said that one of the men killed was a US-allied fighter and said it appeared that gunmen were positioned near the house and attacked the Americans, provoking return fire.
"Our own investigation is continuing and this area is full of Al Qaeda operatives who are not satisfied with our successful work with the Americans," he said. "I cannot rule out that the enemy is trying to sow seeds of division between us and the Americans."
He vowed to keep up the fight against Al Qaeda, but said his fighters would break their alliance with Americans if civilian deaths continued.
"Such actions could have a negative impact on our joint work to root out Al Qaeda," he warned.
American and Iraqi commanders say the Sunni uprising has helped drive Al Qaeda from the belts around Baghdad and forced extremists to hunt for new havens in northern Iraq. As areas have been cleared, more evidence of the brutality of the terror network has been uncovered.
US-backed tribesmen discovered about 50 bodies yesterday in a mass grave in a former Al Qaeda stronghold of Jazeerah near Lake Tharthar, an area northwest of Baghdad where hundreds of bodies have been unearthed in recent months, said Colonel Mazin Younis Hussein, commander of a Samarra police unit.
A suicide bomber also struck the convoy of a sheik working with US forces yesterday in Taji, 12 miles north of Baghdad, killing his nephew and another follower, police and the sheik said.