Most killings of Iraqi civilians by Blackwater security guards on Sept. 16 were unjustified and violated deadly-force rules for security contractors in Iraq, The New York Times reported on Wednesday.

Citing findings by the Federal Bureau of Investigation (FBI), the newspaper said that only three of the 17 killings may have been justified under rules that allow lethal force in response to an imminent threat.

FBI investigators found no evidence to support assertions by Blackwater employees that they were fired upon by Iraqi civilians, which sharply contradicts initial assertions by Blackwater officials, who said that company employees fired in self-defense and that three company vehicles were damaged by gunfire, said the report.

A separate military investigation of the Sept. 16 shootings in Baghdad concluded that all of the killings were unjustified and potentially criminal.

On The New York Times report, Blackwater spokeswoman Anne E. Tyrrell said "if it is determined that one person was complicit in the wrongdoing, we would support accountability in that."

FBI investigation is still under way, but the findings are already under review by the Justice Department.

According to the report, prosecutors have yet to decide whether to seek indictments, but some officials have expressed pessimism that there are no adequate criminal laws to enable them to charge any Blackwater employee with criminal wrongdoing.