A human rights group is calling on the United States to investigate what it calls "newly uncovered" deaths of U.S-led coalition prisoners in Afghanistan.
In an open letter to Defense Secretary Donald Rumsfeld, Human Rights Watch says the newly uncovered cases highlight the U.S. government's failure to establish accountability for abuses.

Earlier, Human Rights Watch had identified three cases, including that of Sher Mohammad Khan who died one day after he was arrested in September during a raid on his family's home near the eastern city of Khost.

But now the rights watchdog has identified two more unreported deaths, taking the toll of deaths in U.S. custody in Afghanistan to six.

The group says four of these cases fall in the category of alleged murder or manslaughter.

Some information for this story provided by AP and AFP.