A Senate investigation accuses the Army of ignoring the situation when a Blackwater subsidiary hired violent drug users to help train the Afghan army and declared "sidearms for everyone" even though employees were not authorized to carry weapons.

The findings by Democratic staff on the Senate Armed Services Committee paint a disturbing picture of lawlessness that contributed to the May 2009 shooting deaths of two Afghan civilians and fed anti-Western sentiment in the region.

"Blackwater operated in Afghanistan without sufficient oversight or supervision and with almost no consideration of the rules it was legally obligated to follow," said Sen. Carl Levin, the committee's chairman.

"Even one irresponsible act by contractor personnel can hurt the mission and put our troops in harm's way," Levin said.

Mark Corallo, a spokesman for the company, which is now known as Xe Services, said management had been acting to correct shortcomings in the program when the shooting occurred.

"The individual independent contractors' actions the night of May 5th clearly violated clear company policies and they are being held accountable," he said in an e-mailed statement.

Former employees of the company's subsidiary Paravant _ Justin Cannon and Christopher Drotleff _ have been charged with killing two Afghans and injuring a third.

Cannon and Drotleff were not supposed to have been armed and had been drinking.

They also probably should not have been hired by Blackwater at all. Drotleff's lengthy criminal record included assault and battery, while his three-year career in the Marines ended after seven unauthorized absences, assault and other charges.

Cannon had been discharged from the Army after going AWOL and testing positive for cocaine, although he later petitioned successfully to have his military records changed to an honorable discharge.

The Senate Armed Services Committee planned to convene a hearing on Wednesday. Among those expected to testify were several former Blackwater contracting officials and contracting officers for the Army.

Levin said he wanted to investigate the circumstances surrounding the 2009 shooting because it was such an obvious example of lax oversight of the estimated 100,000 contractors working in Afghanistan.

Blackwater has been involved in several security incidents, including the 2007 shooting at Nisoor Square in Baghdad, Iraq, that killed 17 people, including women and children. Since the shooting, the North Carolina-based Blackwater renamed itself Xe Services and overhauled its management.

Iraq has pulled the company's license to operate in the country.

Levin said he wants to determine who should be held accountable for the gaps in oversight that led to the 2009 shooting and what should happen to prevent future incidents. He made no suggestion that Xe be barred from working with the U.S. military overseas.

Levin said that among the startling discoveries in his investigation was that contracting personnel acquired several hundred weapons, including more than 500 AK-47s, from a U.S. facility in Kabul that stores the weapons for use by the Afghan police.

The committee obtained a November 2008 e-mail from a company vice president that said, "I got sidearms for everyone... We have not yet received formal permission from the Army to carry weapons yet but I will take my chances."

Corallo called the distribution of weapons without prior authorization a "shortcoming" in the program.

"Though Raytheon, the prime contractor, and the (Defense Department) customer were both aware of Paravant management's decision, and were working to obtain authorization, contractors should not have been armed without the proper approvals," he said.

Army contracting officials did not respond to requests for comment.