Filed by Talib Mutlaq Deewan and the estates of three men killed, Himoud Saed Atban, Usama Fadhil Abbass, and Oday Ismail Ibraheem, the petition claims Blackwater "created and fostered a culture of  lawlessness amongst its employees, encouraging them to act in the  company's financial interests at the expense of innocent human  life", the centre said in a statement.

The petition says the contractor has been paid more than $1bn by the US government since 2001 and that the company violated the federal laws in the September shootout in which 17 Iraqis died.

Recklessness

"Blackwater has turned recklessness into profit at the expense of the lives of innocent civilians," Vincent Warren, the executive director of the centre, said.

He made the comments in a brief interview after the case was filed.

Anne Tyrrell, a Blackwater spokeswoman, said the company was aware of the petition.

"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 on Thursday.

UN concern

Meanwhile, the UN Assistance Mission to Iraq (Unami) has said it is considering charging private security guards hired to support US-led forces in Iraq with war crimes or crimes against humanity for killing civilians.
 
"International humanitarian rights law applies to them as well," Ivana Vuco, a human rights officer with the agency, said on Thursday.
 
"We will be stressing that in our communications with US authorities. This includes the responsibility to investigate to supervise and prosecute those accused of wrongdoing."
 
Unami also expressed concern that too many Iraqi civilians are being killed in US military operations.

In its biannual human rights report released on Thursday, the agency noted several reports of "killings carried out by privately hired contractors with security-related functions in support of US government authorities".

Civilian deaths

 

Guards working for the Australian-owned security company Unity Resources Group killed two women on Tuesday after they fired on an approaching car.

 

Your Views

"Iraq is still under foreign occupation and Iraqis continue to die in great numbers"

albaghawy, Luxembourg

Send us your views

The company said its guards feared a suicide attack and fired only after issuing several warnings for the car to stop.

 

But witnesses have said the vehicle was stationary when it was fired on.

 

Unami called on the US government to establish mechanisms to hold security contractors accountable for unjustified killings and to ensure that offences committed in Iraq "by all categories of US contractor employees" are subject to prosecution under the law.

 

It also demanded the companies respect international humanitarian law, saying increasing reliance on private security firms "risks eroding the fundamental distinction between civilians and combatants because these people may not appear clearly as quite one or the other".

 

'Contractors' immunity'

 

An order issued by the US-led Coalition Provisional Authority in 2004 before the Iraqi government gained sovereignty gives American security companies immunity from Iraqi prosecution on issues arising from their contracts.

 

The UN said the order "enables the US government to waive a contractor's immunity" but "to Unami's knowledge it has not done so to date".

 

The UN report, which covers the period from April 1 to June 30, cited instances in which at least 88 civilians were said to have been killed in air strikes, including seven children who died when helicopters allegedly attacked an elementary school near the Iranian border in the volatile Diyala province.

 

The US military has said it is investigating the report.

 

But the UN agency said the findings of such investigations "are not systematically publicised".

 

It also detailed the alleged killing of 15 Iraqi civilians during US raid and search operations, including a 14-year-old boy.