All 104 people aboard an Afghan airliner that hit a snow-covered mountain last week are dead, authorities said Tuesday, confirming the country's worst air disaster.

NATO and Afghan soldiers managed to inspect the crash site, 20 miles east of the capital, on Monday, finding human remains among the scattered wreckage and deep snow, but no signs of life.

"The troops found that no one was left alive from the crash," said a statement from an Afghan government commission investigating the disaster, offering condolences to the victims' families. "Now the search and rescue operation is complete, the recovery operation has started to investigate the cause of the crash."

The Boeing 737-200 (search) operated by Kam Air (search), Afghanistan's first post-Taliban (search) private airline, vanished from radar screens Thursday after it approached Kabul airport in a blizzard from the western city of Herat (search). There were 96 passengers and eight crew on board, most of them Afghans, but also including nine Turks, six Americans, four Russians and three Italians.

Afghan authorities say the cause of the crash remains a mystery and they are calling in U.S. experts to help investigate. The aircraft's flight recorder has yet to be found.

NATO helicopters spotted part of the wreckage on Saturday, but freezing fog, low clouds and up to 8 feet of snow have limited their visits to the scene to just a few hours so far.

The commission said Tuesday that the plane hit near an old military lookout dating back to the Soviet occupation of the 1980s and that the site was mined.

Relentless snowfall kept government troops from scaling the 11,000-foot Chaperi Mountain anew Tuesday, and it grounded NATO (search) helicopters poised to ferry medics and investigators from Kabul airport.

Officials say it could take weeks to collect the bodies, fueling the frustration of relatives worried about the fate of the remains.

At a checkpoint about three miles from the foot of the mountain, about 40 people peered through the gloom at the invisible mountain, and harangued the Kabul police chief to let them go and search for themselves. Gen. Baba Jan eventually allowed two vehicles through, with an escort of police cars and German armored vehicles.

"If they cannot do it, they should announce it and the people of Kabul will help us. Thousands of volunteers will come," said Noora Jan, whose 27-year-old son was on board.

Kam Air resumed flying Tuesday, but one of its jets carrying 220 passengers turned away from the Afghan capital faced with the same conditions that accompanied last week's disaster. The airline said the plane returned to Dubai.