The chairman of the American security company Blackwater USA is defending his company's guards, who are under investigation over a September shooting incident in which 17 Iraqis were killed. VOA's Sean Maroney reports from Washington.

The Iraqi government accuses Blackwater guards of a deliberate, unprovoked shooting spree that killed 17 people in Baghdad on September 16.

But Blackwater chairman Erik Prince says, according to incident reports he has seen, the guards were responding to small arms fire while escorting a diplomatic convoy.

"There was no deliberate murder, no deliberate violence by our guys," said Erik Prince. "They've done 16,500 personal security detail-type missions just like this one on September 16th - 16.5 thousand since 2005 [and] less than one percent resulted in any discharge of a firearm by our people."

A committee report in the House of Representatives says Blackwater was involved in 195 shooting incidents since 2005, and had to fire 122 personnel for improper conduct, including misuse of weapons and alcohol and drug violations.

During an appearance on CNN's Late Edition, Prince also said there was no basis for a lawsuit filed last week by the Center for Constitutional Rights. The suit accuses Blackwater of murder and war crimes, and it seeks unspecified damages on behalf of one survivor and the families of three of those who died.

Prince contends the suit is politically motivated.

"The trial lawyers who filed this lawsuit are the same guys that defended the World Trade Center bombings in 1993, the Blind Sheik, and defended a bunch of killers of FBI agents and other cops," he said. "So, this is very much a politically motivated lawsuit for media attention."

Currently, private American security firms in Iraq are immune from both Iraqi and U.S. military laws. However, the House of Representatives approved legislation that would subject contractors to prosecution by U.S. courts, and similar legislation is expected to be introduced in the Senate.

The U.S. Federal Bureau of Investigation is investigating the September 16 incident to allow for the possibility that it might lead to the prosecution of Blackwater agents by the Justice Department.

Meanwhile, the State Department has also ordered tighter oversight of private security firms. U.S. security officers will now ride along on all diplomatic convoys guarded by Blackwater in Baghdad. Video equipment inside of convoy vehicles will also record any security incidents, and radio transmissions from the convoys to the U.S. Embassy will be recorded.

Prince says he welcomes the added safeguards.

"We actually asked for that a year-and-a-half ago in writing to the State Department," said Prince. "We are tired of having it be our guy's word against someone else in an incident. Let it be a third party. Let the video camera record, or let it be a State Department staff Diplomatic Security Agent out there riding in the cars."

Blackwater USA is one of three private security firms the State Department employs in Iraq with about 1,000 employees. Since 2001, the firm has secured U.S. government contracts worth more than a $1 billion.