The US military has failed to conduct proper investigations into the killings of Iraqi civilians by American soldiers in Baghdad, a human rights group says.
The report says US troops are not prepared to police Iraq
In its new report, New York-based Human Rights Watch accuses the military of acting with virtual impunity in the Iraqi capital and using excessive or indiscriminate force.
The group says it has confirmed that 20 civilians have been killed in Baghdad by US troops since President George W Bush declared the end of major combat operations on 1 May.
In response, Pentagon spokesman Army Major Joseph Yoswa said US troops went to "extraordinary lengths to avoid civilian casualties", but added that unintended consequences are inevitable in any conflict.
Major Yoswa said that the "the rare circumstances" where a US soldier was accused in the death of a civilian "are always thoroughly investigated and corrective actions are taken".
The alleged misuse of force by American troops has already been the source of tension between members of the US-appointed Iraq's Governing Council and the US-led occupation coalition.
The 56-page report entitled "Hearts and Minds: Post-War Civilian Casualties in Baghdad by US Forces" says 20 civilians were killed in Baghdad between 1 May and 30 September.
Anti-American feelings run high among many Iraqis
The group also says it has credible reports of 94 civilian death in the city "under questionable circumstances" that need to be urgently investigated.
"It's a tragedy that US soldiers have killed so many civilians in Baghdad," said Joe Stork, acting executive director of the Middle East and North Africa division at Human Rights Watch.
"But it's really incredible that the US military does not even count these deaths. Any time US forces kill an Iraqi civilian in questionable circumstances, they should investigate the incident," Mr Stork added.
The group says that part of the problem is that many of the same US troops who have fought their way into Baghdad were not trained, equipped or psychologically prepared for policing the country.
Human Rights Watch acknowledges that the US military does not deliberately target civilians, but accuses some soldiers of being trigger-happy.
The US military has completed five investigations above the division level into alleged unlawful deaths of Iraqi civilians, the report says.
It says that in four cases, soldiers were found to have acted "within the rules of engagement".
In the fifth case, a helicopter pilot and his commander face disciplinary action for trying to tear down a Shia banner in Baghdad, which triggered a violent clash with protesters on 13 August.
The group said that after conducting its own investigation into two of the five incidents it found evidence to suggest that soldiers used excessive forces.
"The cases we documented in this report reveal a pattern of over-aggressive tactics, excessive shooting in residential areas and hasty reliance on lethal force," Mr Stork said.
"Right now soldiers feel they can pull the trigger without coming under review," he added.
Human Rights Watch says its report is based on more than 60 interviews, police records and media accounts, and also collected information from the US military and human rights groups.