Fresh snow dimmed hopes on Tuesday that troops could retrieve the first bodies from the wreckage of an Afghan jetliner that crashed into a freezing mountaintop last week with the apparent loss of all 104 people on board.

NATO (search) soldiers on Monday found human remains but no survivors at the crash site 20 miles east of Kabul and plans were laid to fly Afghan medical teams and investigators to the scene to begin the gruesome task of collecting body parts.

But an Afghan army spokesman said troops who tried to camp near the site had been forced to descend by the freezing temperatures, while heavy cloud cover was keeping helicopters on the ground.

"They'll try to go back up on foot today, but the best chance is from the air," spokesman Maj. Mohammed Arif Anes said. "We need God's help."

The Boeing 737-200 (search), flown by Kam Air, Afghanistan's first post-Taliban private airline, vanished last Thursday after it approached Kabul airport in a snowstorm from the western city of Herat.

Officials expect all 96 passengers and eight crew — most of them Afghans, but also including more than 20 foreigners — perished in what would be Afghanistan's worst aviation disaster.

NATO helicopters spotted parts of the wreckage some 11,000 feet up Chaperi Mountain (search) on Saturday, but freezing fog, cloud and up to eight feet of snow have hampered the recovery operation.

Five Slovenian mountain troops who inspected the crash site for two hours on Monday saw parts of the tail, the engines and scattered seats but the cabin has yet to be found, alliance spokeswoman Maj. Karen Tissot Van Patot said.

Officials say it could take weeks to collect all the bodies, fueling the frustration of relatives worried about scavenging animals and fast-spreading rumors that looters may have already reached the crash site.

"A hand might be here and a foot somewhere else, so it will very difficult," said Gen. Mohammed Zahir Azimi, a Defense Ministry spokesman. "As well as the cold and the snow, there could be mines up there."

The Afghan government is calling in U.S. experts to help investigate, and presidential spokesman Jawed Ludin said Tuesday that Boeing would also be asked to help an independent inquiry into the crash.

Ludin said the aircraft's flight recorder had yet to be found.

He also said that "everything that's in our control will be done to compensate for the loss of those who perished." He didn't elaborate.

Nine Turks, six Americans and three Italians were believed to have been on the plane, though a final list has yet to be released. The airline says the crew was made of up of six Russians and two Afghans, although Moscow said only four Russian citizens were missing.