WASHINGTON, May 4: Twenty-five prisoners have died while being held by US forces in Iraq and Afghanistan and two of them were murdered in Iraq by Americans, US Army officials said on Tuesday.

An Army official said one soldier was convicted of murder in the military justice system for shooting a prisoner to death in September last year at a detention centre in Iraq, and another prisoner was killed at the Abu Ghraib jail in November by a private contractor who worked as an interrogator for the CIA.

The soldier was reduced in rank to private and thrown out of the service but did not serve any jail time, the official said. The official said the soldier shot the prisoner after he had allegedly thrown rocks at the soldier, and the soldier was found to have used excessive force.

The official said because the CIA contractor was not in the US military no legal action was taken because of lack of jurisdiction, but Army officials referred the case to the Justice Department for possible action. The official did not offer details of this killing.

The official did not identify the Americans involved in the murders or the victims.. Most of the deaths took place in Iraq. Word of these investigations came as the Pentagon investigated the abuse of Iraqi prisoners by US forces at the Abu Ghraib jail, outside Baghdad, which has inflamed anti-American sentiment, especially in the Arab world.

The official said a third death among the 25 being investigated was ruled a justifiable homicide, saying it occurred while a prisoner was attempting to escape. Of the other 22 death investigations involving prisoners in Iraq and Afghanistan, 12 prisoners were found to have died either by natural or undetermined causes.

The Army did not say in which countries the 25 killings occurred but said the vast majority were in Iraq, not Afghanistan. -Reuters