DASHT-E LEILI, Afghanistan — Seven years ago, a convoy of container trucks rumbled across northern Afghanistan loaded with a human cargo of suspected Taliban and al Qaida members who'd surrendered to Gen. Abdul Rashid Dostum, an Afghan warlord and a key U.S. ally in ousting the Taliban regime.

When the trucks arrived at a prison in the town of Sheberghan, near Dostum's headquarters, they were filled with corpses. Most of the prisoners had suffocated, and others had been killed by bullets that Dostum's militiamen had fired into the metal containers.

Dostum's men hauled the bodies into the nearby desert and buried them in mass graves, according to Afghan human rights officials. By some estimates, 2,000 men were buried there.

Earlier this year, bulldozers returned to the scene, reportedly exhumed the bones of many of the dead men and removed evidence of the atrocity to sites unknown. In the area where the mass graves once were, there now are gaping pits in the sands of the Dasht-e-Leili desert.

A U.N.-sponsored team of experts first spotted two large excavations on a visit in June, one of them about 100 feet long and more than 9 feet deep in places. A McClatchy reporter visited the site last month and found three additional smaller pits, which apparently had been dug since June.

Faqir Mohammed Jowzjani, a former Dostum ally and the deputy governor of Jowzjan province, where the graves were located, told McClatchy that it's common knowledge that Dostum sent in the bulldozers.

He speculated that Dostum wanted to destroy the evidence because of local political trouble that could have made him more prone to prosecution for the killings.

Last year, Dostum and the then-Jowzjan governor became embroiled in a feud that killed seven people and wounded more than 40. This year, Dostum and his men kidnapped and reportedly beat a rival Afghan leader.

"Maybe General Dostum did it because of a fear of prosecution in the future," Jowzjani said.

Another local Afghan official said that Dostum had begun to worry that the 2001 killings could come back to haunt him. "Everyone in the city (Sheberghan) knows that the evidence has been removed," said the official, who spoke on the condition of anonymity because of worries about being killed for talking about the subject.

"When the crime happened, (Dostum and his commanders) didn't think they would ever be prosecuted," the official said. "But later they began to worry . . . they have taken all the bones and thrown them into the river" that's about half a mile from the graves.

NATO — which has command authority over a team of troops less than three miles from the grave site — the United Nations and the United States have been silent about the destruction of evidence of Dostum's alleged war crimes.

"The truth is that General Dostum went out with bulldozers and dug up those graves," Jowzjani charged. "I don't know why UNAMA" — the U.N. mission in Afghanistan — "hasn't said anything in this regard . . . maybe because of fears about his power, or maybe they made a deal."

Gen. Ghulam Mujtaba Patang, the commander of Afghanistan's national police in the north, said that he knew that the graves had been emptied. He noted that "the digging was done very professionally" and said that U.N. and NATO-led teams in the area were also aware. (While provincial reconstruction teams are led by individual nations, their military components are under NATO command.)