WASHINGTON - Blackwater USA founder Erik Prince defended his company Tuesday from an onslaught by House Democrats, who portrayed the defense contractor as an overpaid private army that is harming U.S. interests in the Middle East.

Prince, whose company has secured more than $1 billion in federal contracts, said Blackwater guards operated properly in a Sept. 16 melee in a Baghdad square that left as many as 11 Iraqi civilians dead and ignited an uproar over the use of private military contractors.

"Based on everything we currently know, the Blackwater team acted appropriately while operating in a very complex war zone on Sept. 16," Prince said in prepared testimony for a packed hearing of the House Oversight and Government Reform Committee. "There has been a rush to judgment."

Iraqi officials say Blackwater guards fired unprovoked on Iraqi vehicles that day, killing, among others, a baby and a mother of eight.

The committee did not probe the incident at the request of the Justice Department, following the announcement Monday that the FBI was joining a State Department investigation.

Blackwater, which has headquarters in Moyock, N.C., and under contract to protect U.S. diplomats and other civilians in Iraq, has been involved in many other incidents in which apparently innocent Iraqis were killed, according to a report Monday by committee chairman Rep. Henry Waxman, D-Calif. It disclosed that company security specialists were involved in 195 "escalation of force" incidents involving the firing of shots since 2005.

Rep. Carolyn Maloney, D-N.Y., chastised Prince for Blackwater's response to an incident on Christmas Eve 2006 in which a drunken employee killed a bodyguard to Iraq's vice president, and was whisked out of Iraq with the State Department's knowledge.Prince said the man had been fired and fined. But an internal Blackwater e-mail message released at the hearing showed that he merely forfeited bonuses and a return air ticket worth a total of $14,697.

"If he lived in America, he would have been arrested, and he would be facing criminal charges. If he was a member of our military, he would be under a court-martial. But it appears to me that Blackwater has special rules," Maloney said.

"We fired him. We fined him. But we as a private organization can't do any more. We can't flog him. We can't incarcerate him," Prince said in response to questions by Rep. Elijah Cummings, D-Md., about the same incident.

It is that apparent lack of accountability that has caused growing scrutiny of the burgeoning private security industry.

No private military contractor has been criminally prosecuted for alleged wrongdoing in Iraq.

Many of the committee's Republicans complained that the hearing was a partisan attempt to smear a firm with strong ties to the GOP. Prince's sister, Betsy DeVos, is a former chairwoman of the Michigan Republican Party, and her family has made large contributions to the GOP.

Republicans also repeated Blackwater's argument that the company is supporting the U.S. mission in Iraq, and that no diplomats or lawmakers visiting Baghdad have been killed or seriously wounded while under Blackwater's protection.

"That should account for something," said Rep. Dan Burton, R-Ind.