Four US contractors for the company formerly known as Blackwater were not authorised to carry weapons when they were involved in a deadly shooting in Afghanistan this month, the US military said today.

IRAQ said yesterday it will bar Blackwater Worldwide from providing security protection for US diplomats because its contractors used excessive force, sanctioning a company whose image was irrevocably tarnished by the 2007 killings of 17 Iraqi civilians.

BLACKWATER Worldwide supports “stringent accountability” for any wrongdoing, a spokeswoman said, following a report saying federal investigators found that the shooting deaths of at least 14 Iraqi civilians by its guards violated rules of deadly force.

US government agents have found that the killing of at least 14 of the 17 Iraqi civilians shot by Blackwater Worldwide security guards were unjustified and broke rules for using deadly force, it was reported today.