An avalanche triggered by a massive earthquake in Nepal smashed into a base camp at the foothills of Mount Everest today, killing at least eight climbers and guides.
Many others were injured and an unknown number have been reported as missing near the mountain's most dangerous spot, officials said.
The avalanche struck between the Khumbu Icefall, a notoriously treacherous rugged area of collapsed ice and snow, and the base camp where most climbing expeditions are, said Ang Tshering of the Nepal Mountaineering Association.
Gyanendra Shretha, an official with Nepal's mountaineering department, said the bodies of eight people had been recovered and an unknown number remain missing or injured.
Their nationalities were unclear as climbers described chaotic attempts to treat the injured amid fears of more landslides and aftershocks that continue to rattle the region.
Chinese media reported a Chinese climber and two Sherpa guides were among the dead.
The world's highest mountain is scaled by hundreds every year who brave extreme weather, a hostile terrain and unpredictable avalanches, one of which killed 16 Sherpa guides almost exactly a year ago.
"Right now, it is pretty chaotic and we try to help those injured," Danish climber Carsten Lillelund Pedersen wrote in an email to Danish news agency Ritzau.
He said that "it is hard to imagine that there are no dead". He said people suffered head injuries, broken legs and "we have supported one who got hit by a flying stone".
Norwegian climber Teodor Glomnes Johansen told a newspaper in Norway that they are working on saving lives. He was at the base camp that was partly smashed.
"We carry out severely injured people. This is pretty tough and heavy. We do not know whether there will be more avalanches," Mr Glomnes Johansen told Norway's VG newspaper.
"All those who are unharmed organise help with the rescue efforts. Men, women and Sherpas are working side by side. The job right now is to assist the doctors in the camp here."
Carsten Lillelund Pedersen said that he and a Belgian companion were at the Khumbu Icefall, close to the base camp at an altitude of 16,500ft, when the earthquake hit.
"We are starting to receive the injured, the most severe of them with many fractures, he was blown away by the avalanche and broke both legs. For the camps closer to where the avalanche hit, our Sherpas believe that a lot of people may have been buried in their tents," he wrote on Facebook.
He said that a steady flow of people were fleeing the base camp for more secure areas down the mountain.
Local reports in China said an amateur team encountered an avalanche on the north slope of the mountains at an elevation of more than 22,965ft and safely retreated to a camp at a lower elevation.
Thomas Frese Carlsen, a Danish schoolteacher who was in Nepal with 12 students from Denmark, said that rumours of another quake forced many to sleep out in the open.
"We will sleep outside tonight, on the lawn," he told Denmark's TV2 channel. He described the quake as "freakin' wild."
Climber Robin Trygg told the Swedish news agency TT his Sherpa guides had been in radio contact with other guides on Everest and that they reported an avalanche there hitting as many as 80 people.
"We were sitting in the tent and drinking tea when the earth, all of a sudden, began shaking. We didn't understand what happened," he told the news agency by telephone.
The magnitude-7.8 quake struck around noon local time about 50 miles north-west of Kathmandu, almost one year after the deadliest avalanche on record hit Everest killing 16 Sherpa guides on April 18, 2014.
Following the 2014 disaster, the guides accused Nepal's government of not doing enough for them despite making millions in permit fees from the western mountaineers who attempt to scale the Himalayan peaks.
The guides protested by refusing to work on the mountain, leading to the cancellation of last year's climbing season.