BAGHDAD - The target was in the house. US forces made their move. But as they neared the building in a lush farming area south of Baghdad, gunmen emerged from the dark.
When the shooting ended, two US-allied civilian security guards were dead, along with a companion apparently linked to the security force.
The US Army said yesterday it appeared that the Iraqi guards had left their assigned checkpoint in the village of Jarf Sakhr and were mistaken for insurgents.
It was the second case in a week of civilian guards being killed by US forces in the area, and the third such incident this month in Iraq, where the security corps' cooperation with US and Iraqi troops is key to maintaining recent security gains.
Since the latest shooting, some of the guards, who are known as Sons of Iraq or concerned local citizens, have abandoned their checkpoints to protest what they consider to be careless US behavior.
Colonel Tom James of the US Army's Fourth Brigade, Third Infantry Division, said the Friday shooting could have been avoided had the civilian guards followed rules outlined in contracts they signed with the military. Those rules include remaining at checkpoints and not taking offensive action, which could cause soldiers to mistake them for insurgents, he said.
"We're very strict in our approach to the Sons of Iraq, what they can and cannot do, how they have to be in their positions and be static," he said. "A situation like this occurs because they are not following those particular rules."
But his description of the event Friday also underscored the difficulty of conducting missions in volatile regions with a mix of uniformed and nonuniformed forces that operate in close proximity but are unable to communicate with one another.
Sons of Iraq members, who are on the payroll of the US military, are not in direct contact with US forces and are not told beforehand of planned operations. That means if they see figures moving in the distance in the night, they have no way to know if they are friend or foe until the figures get close to their checkpoints.
With attacks on their checkpoints increasing dramatically since Osama bin Laden publicly condemned the volunteers in a December statement, leaders say they have reason to be edgy.
"It's a very, very complex environment out there," said Navy Rear Admiral Gregory Smith, a military spokesman. He cited the close proximity of operations to some civilian checkpoints, the suspected infiltration by insurgents of some Sons of Iraq units, and the confusion that occurs when shots ring out in the dark.
In some instances it turned out there were security guards shooting, he said. "What's unknown to us is precisely what they thought they were shooting at."
"Without appointing blame or suggesting that we're always in the right, we certainly conduct our operations to be as precise as we can," Smith said.
After the gun battle, the Americans continued toward the house, where they captured two suspected insurgents.
Only later did they learn that two of the dead were registered Sons of Iraq soldiers who had been approved for security work after passing US background checks, James said. The third was a friend of a sheik who oversees the Sons of Iraq program in the area.