The Iraqi government is disputing the account by Blackwater security guards over a weekend shooting in Baghdad that it now says killed 20 Iraqis and wounded scores of others.
Ali Dabbagh, the Iraqi government spokesman in Baghdad, told ABC News that a preliminary Iraqi report says Blackwater security guards opened fired at a car when it failed to come to a complete stop at a checkpoint, ignoring a police warning to stop. The initial shots killed an Iraqi couple and their baby.
Blackwater officials have argued that their guards were firing in response to a car bomb and were being ambushed by Iraqi insurgents.
The investigation into a firefight between Blackwater USA personnel and Iraqi civilians has led to greater scrutiny of the role of private contractors in Iraq.
The Pentagon and Iraqi government announced today that a joint State Department-Iraq investigation will look into the incident and, among other things, try to determine whether the victims were insurgents or innocent Iraqis.
"This is not the first time this company has committed violations," said Iraqi Prime Minister Nouri Kamel al-Maliki on state-run TV. "It is our responsibility as a government to protect the lives of civilians."
The Iraqi government has barred Blackwater from operating in Iraq, but said it didn't intend to ban the company forever. Iraqi officials said they want to ensure these contractors and others like them are held accountable for their actions.
"We are not intending to stop them from operating in Iraq," Dabbagh told ABC News. But he said, "we do need them to be kept accountable."
The Iraqi report also says Blackwater helicopters had fired on Iraqis — an accusation the company has denied.
"The helicopters providing aerial support never fired weapons," said Anne Tyrrell, spokeswoman for Blackwater USA, in a written statement provided to ABC News Tuesday.
"The 'civilians' reportedly fired upon by Blackwater professionals were in fact armed enemies and Blackwater personnel returned defensive fire," Tyrrell said.
U.S. Embassy officials had said Monday the guards were responding to a car bomb. However, Iraqi officials have said the car bomb was too far away for the Blackwater forces to be threatened by it.
"We know the convoy came under attack. What happened before, during and after is the subject of the investigation. And I think we need to let that investigation play out before I or anyone else is really in a position to assert definitively what we think happened," Tom Casey, deputy State Department spokesman, said today.
The Blackwater contractors in question are still in Iraq and will be part of the investigation, U.S. Embassy spokeswoman Mirembe Nantongo said today.
Investigators are looking into whether Blackwater violated rules of engagement that the military set up for private security contractors. The rules are secret, but a declassified copy obtained by ABC News says they must "fire only aimed shots" and "with due regard for the safety of innocent bystanders" — rules similar to those that apply to U.S. troops.
A confidential report obtained by ABC News from the U.S. Embassy Baghdad said five Blackwater security guards were involved in the firefight when a car bomb went off northwest of the Green Zone.