The US military says its troops behaved correctly during an incident in which they opened fire in the Iraqi town of Falluja and killed eight policemen.
Survivors' accounts are at odds with the US version of events
The initial findings of an American investigation into the firefight earlier this month - in which a Jordanian hospital guard was also killed - are that the troops acted "within the construct of the military's rules of engagement".
The US commander in Iraq, Lieutenant General Ricardo Sanchez, said the investigation was still undergoing final review but added: "The initial reports were clear. There was initial fire and it was a 30-second engagement. At the end of it, the policemen were dead."
His remarks appeared to be at odds with reports of the incident by Iraqi policemen injured in the 12 September incident.
Several of them said the firing began as several Iraqi police vehicles approached a US checkpoint near the Jordanian military hospital on the outskirts of Falluja, 50 kilometres (30 miles) west of Baghdad.
The police, all members of the local US-trained force, were chasing a car carrying several wanted gunmen.
It appears there were three police vehicles - one an unmarked pick-up with a rear-mounted machine gun - chasing a fourth vehicle containing gunmen.
The surviving policemen said they had begged the American soldiers to stop shooting, screaming in Arabic and English that they were police officers.
But the troops kept firing for between 30 minutes and an hour, they added.
Falluja, a stronghold of supporters of ousted Iraqi dictator Saddam Hussein, has been the scene of frequent clashes involving US troops.
Correspondents say anti-US resistance has been strong in the town since American troops killed 16 demonstrators there in April.