BAGHDAD — An official Iraqi investigation into a deadly shooting involving Blackwater USA security guards raised the number of Iraqis killed to 17 and found the gunfire was unwarranted, the government said Sunday. It also said the shootings amounted to a deliberate crime and recommended those involved face trial.

The Blackwater guards are accused of opening fire on Iraqi civilians in a main square in Baghdad on Sept. 16. They claimed they came under fire first.

The Iraqi investigative committee, which was ordered by Prime Minister Nouri al-Maliki, found that convoys from the Moyock, N.C.-based security company did not come under direct or indirect fire before the men shot up the intersection.

"It was not hit even by a stone," government spokesman Ali al-Dabbagh said in a statement.

The incident has outraged Iraqis and brought calls for an overhaul to the rules governing private contractors such as Blackwater, which provides heavily armed security for U.S. diplomats serving in Baghdad.

The three-member Iraqi panel led by Defense Minister Abdul-Qader al-Obeidi determined that Blackwater guards sprayed western Baghdad's Nisoor Square with gunfire without provocation.

The panel raised the casualty toll to 17 Iraqis killed and 23 wounded, as opposed to the 11 deaths Iraqi officials originally reported.

On Thursday, Minister of State for National Security Sherwan al-Waili told The Associated Press that the panel had determined 13 Iraqis had been killed. A parallel but unofficial investigation by the Interior Ministry also put the number at 17.