A report compiled by the soldiers concluded that there was "no enemy activity involved" and called the incident a "criminal event," the Post reports.
"It appeared to me they were fleeing the scene when they were engaged," said Lt. Col. Mike Tarsa, whose soldiers arrived at the scene 20 to 25 minutes after the shootings ended. "It had every indication of an excessive shooting."
The soldiers' conclusions - based upon their own observations, eyewitness interviews and discussions with Iraq police - are similar to those reached by the Iraqi government and contradict Blackwater's contention that its guards acted in self-defense after being shot at by the Iraqis.
"I did not see anything that indicated they were fired upon," said Tarsa, commander of the 3rd Battalion, 82nd Field Artillery Regiment of the 2nd Brigade, 1st Cavalry Division.
He also said several Iraqi drivers had apparently made U-turns and were heading away from the intersection when their cars were hit by gunfire from the Blackwater guards.
On Thursday, families of the Iraqis killed in the shooting filed suit against Blackwater in a U.S. court, saying the firm violated American law and fostered a culture of lawlessness among its employees.
The suit in U.S. District Court in Washington, D.C., said the contractor has been paid more than $1 by the U.S. government since 2001 and that the company violated U.S. laws in the Sept. 16 killings.
"Blackwater has turned recklessness into profit at the expense of the lives of innocent civilians," said Vincent Warren, executive director of the Center for Constitutional Rights, which brought the suit. Warren made the comments in a brief interview after the suit was filed.
Blackwater spokeswoman Anne Tyrrell said the company was aware of the lawsuit. "Because it is a matter currently under investigation by the FBI, we will refrain from commenting on the specifics of the case other than to say that the company will defend itself vigorously," she said.
In other developments:
The FBI arrived in Baghdad a week ago to investigate the Sept. 16 shootings, taking over a State Department investigation and raising the prospect that it could be referred to the Justice Department for prosecution.
Blackwater protects U.S. diplomats as they move about on Baghdad's dangerous streets. An Iraqi investigation into the killings recommended that the State Department sever all contracts for the company's operations in Iraq within six months.
Blackwater should be liable for claims of assault and battery, wrongful death, intentional and negligent infliction of emotional distress, and negligent hiring, training and supervision, the lawsuit says.
The plaintiffs in the case are an injured survivor and three familes of men who died in the incident.
The United States has not made conclusive findings about the shooting, though there are multiple investigations under way and Congress has opened inquiries into the role of private security contractors.
The Iraqi government report said its courts were the proper venue in which to bring charges.
Iraqi officials say Blackwater's license to operate in Iraq expired on June 2, 2006, meaning it had no immunity from prosecution under Iraqi laws set down after the fall of Saddam Hussein in 2003.
The State Department has counted 56 shooting incidents involving Blackwater guards in Iraq this year. All were being reviewed as part of the comprehensive inquiry ordered by Secretary of State Condoleezza Rice.