Mass graves raise questions in Afghanistan

How did Taliban prisoners die, and who knew?

An unknown number of Taliban fighters were dumped in mass graves last year.

MAZAR-E SHARIF, Afghanistan (CNN) -- In the stifling desert of northern Afghanistan, lying as still as the air, is evidence of the gruesome fate that met hundreds of Taliban fighters late last year.

The discovery of numerous mass graves, filled with bones and skulls, raises questions about exactly what happened to prisoners after they were captured last November in the northern city of Konduz by the U.S.-backed forces of Northern Alliance Gen. Adbul Rashid Dostum.

The ground around Mazar-e-Sharif offers abundant evidence of mass death. In May, investigators with the Boston, Massachusetts-based group Physicians for Human Rights examined a grave in Dasht-e-Leili and said hundreds of victims had been dumped there.

CNN NewsPass VIDEO CNN's Matthew Chance reports on the unearthing of graves in Afghanistan with remains of Taliban prisoners who may have suffocated at the hands of the U.S.-backed Northern Alliance. (August 29) Play video

But how and why the men died is still uncertain.

Human-rights groups have accused Afghan forces of suffocating hundreds of Taliban fighters by locking them in unventilated steel shipping containers after their capture. The captives were taken to a prison in Sheberghan, some 200 miles from Konduz.

Not all of them were dead on arrival. Many are still behind bars at Sheberghan, where they told CNN of their surrender and the aftermath.

They said they were packed tightly into trucks and shipping containers for the trip to the prison, and that many of their Taliban comrades did not survive.

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"We don't know how many people died," one prisoner said. "We know that we were about 12,000 people, and now there is only 4,000 or 3,500. We don't know where are the other people."

U.N. investigators hope to unlock the mystery, and outside Mazar-e-Sharif, they are standing watch over a patch of desert where as many as 1,000 Taliban fighters may be buried.

Initial findings appear to support the contention of human-rights groups -- that the men were suffocated in shipping containers, then dumped.

Dostum admits as many as 200 captives died en route to the prison. But he would not elaborate on how much the United States knew or approved of his treatment of the war prisoners.

He is adamant, though, that U.S. forces were not present when the prisoners were loaded into shipping containers.

Gen. Tommy Franks, the commander of U.S. forces in Afghanistan, has said he supports an investigation into the deaths of the Taliban fighters. And State Department spokesman Philip Reeker recently said, "We're going to continue to engage Afghan authorities on this matter in order to help seek accountability for any violations that may have occurred."

But with new and old graves scattered around Afghanistan -- a country that endured more than 20 years of civil war before the U.S.-led air campaign led to the fall of the Taliban last year -- it may take years to find out what happened and who should bear responsibility.