A human rights group has said it knows of more prisoners dying in US military custody in Afghanistan than previously revealed and has called on Washington to reveal details of the cases.
In an open letter to US Defence Secretary Donald Rumsfeld, Human Rights Watch (HRW) revealed two new cases of deaths in custody and demanded an investigation into a third that took place three months ago.
"It's time for the United States to come clean about crimes committed by US forces in Afghanistan," said Mr Brad Adams, Asia Division director for Human Rights Watch.
A spokesman for the US Army's Criminal Investigation Command in Washington later told of another two prisoners who had died in US detention, bringing the total number to eight.
The two new cases mentioned by the HRW in its letter to Mr Rumsfeld involved the death of an Afghan army soldier mistakenly arrested with seven others in March last year, and the suspected murder of another detainee in 2002, HRW said.
The soldier, Jamal Naseer, died at the US base at Gardez, southeast of Kabul in March, 2003. The army opened an investigation into the case in May, 2004, the group said.
Men detained with Mr Naseer have said US forces punched them, kicked them, hung them upside down, and hit them with sticks or cables. Some said they were soaked in cold water and forced to lie in snow, and given electric shocks to their toes, HRW said in its letter.
The rights group also said there was another previously unpublicised suspected murder of an Afghan detainee by four US soldiers in Afghanistan in or before September 2002.
US Defence Department documents released to the American Civil Liberties Union in the past week show the Army opened an investigation in September, 2002. HRW says the document states that a captain and three sergeants murdered the Afghan, but it does not know if anyone was prosecuted.
The Army Criminal Investigation Command spokesman identified the dead man as M. Sayari and said he died on August 28th, 2002. The investigation had closed, and the case was adjudicated by the Army, the spokesman said without giving further details.
The most recent reported death in custody was that of Sher Mohammad Khan, who died, HRW said, after being arrested during a raid at the village of Lakan in southeast province of Khost on September 24th.
The US military said Khan died of a heart attack; his brother was shot dead in the same raid.