U.S. security contractor Blackwater, under investigation over deadly incidents in Iraq, defended its role there on Tuesday, but lawmakers took aim at the company's actions in a Sept. 16 shooting in which 11 Iraqis were killed. Blackwater founder and former Navy SEAL Erik Prince said in in testimony prepared for the House of Representatives Committee on Oversight and Government Reform that his staff acted "appropriately" on that day in a very complex war zone.

"There has been a rush to judgment based on inaccurate information, and many public reports have wrongly pronounced Blackwater's guilt for the deaths of varying numbers of civilians," Prince said in the testimony.

"Congress should not accept these allegations as truth until it has the facts," added Prince.

Iraq's government has been strongly critical of Blackwater and has called the shooting incident a crime.

Committee chairman Henry Waxman, a California Democrat, said there were serious questions about Blackwater's performance and that the Sept. 16 shooting was just the latest in a number of "troubling" incidents.

"Is Blackwater, a private military contractor, helping or hurting our efforts in Iraq," Waxman asked in his opening statement.

"Blackwater will be accountable," he added.

Blackwater, which has received U.S. government contracts worth more than a billion dollars since 2001, is under intense scrutiny over its security work in Iraq, where Prince said the North Carolina firm had about 1,000 personnel.

The hearing comes amid growing questions over the role of private contractors in Iraq and whether the U.S. government relies too heavily on outsiders to perform jobs traditionally done by the military.