WASHINGTON, May 8: The US military has punished two Army Reserve soldiers who assaulted prisoners while working as guards at the Guantanamo Bay prison for terrorism suspects, defense officials said on Friday.

A third guard was acquitted in a court-martial of criminal charges after using pepper spray on a prisoner and a fourth guard was given counseling after admitting to kicking the bed of a prisoner inside a hospital at the U.S. naval base at Guantanamo Bay, Cuba, said Air Force Maj. Michael Shavers, a Pentagon spokesman.

Allegations of misconduct by two other guards were not substantiated, Shavers said. The United States holds at Guantanamo about 600 non-U.S. citizens caught in what President George W. Bush calls the global war on terrorism.

Human rights groups long have criticized the conditions under which prisoners are held at Guantanamo, and the announcement came as the United States faced withering criticism for the abuse and humiliation of prisoners at the hands of American forces in Iraq.

An Army Reserve specialist was charged with dereliction of duty and assault on a detainee following an incident in April 2003, Shavers said. The guard was accused of hitting a prisoner who already had been subdued.

In noncriminal punishment, the guard was reduced in rank to private, given 45 days of extra duty and reassigned to other duties, officials said.

ANOTHER GUARD: Another Army Reserve specialist was charged with assault in September 2002 in an incident in which the guard sought to spray a prisoner with a hose after the prisoner threw what was believed to be toilet water at the guard. The guard was reduced in rank to private - although that rank reduction was later reversed - and was given seven days of restricted movement and reassigned to other duties.

"What this shows is that we have a very good system at Guantanamo Bay in that if there are credible allegations of mistreatment or abuse of detainees that we take swift action to address those," Shavers said.-Reuters