KATHMANDU, Nepal — Mountaineers, guides and porters streamed from Mount Everest base camp on Sunday in the wake of a deadly earthquake-triggered avalanche that obliterated parts of the rocky village of nylon tents. Some warned that dozens of people may still be missing.
The worst injured were ferried out in helicopters, while those remaining at base camp endured a series of powerful aftershocks, some of which caused smaller but still terrifying avalanches in the surrounding mountains.
The avalanche on Saturday, set off by the massive earthquake that struck Nepal, left at least 18 people dead and dozens more injured. Overall, the quake killed more than 2,500 people.
But as the first stunned survivors of the avalanche reached Kathmandu, Nepal’s capital, they said that dozens of people may still be missing and were almost certainly dead.
‘‘The snow swept away many tents and people,’’ said Gyelu Sherpa, a sunburned guide among the first group of 15 injured survivors to reach Kathmandu.
The 15, most of them Sherpa guides or support staff working on Everest, flew from Lukla, a small airstrip not far from Everest. None were believed to be facing life-threatening injuries, but many limped to a bus taking them to a nearby hospital, or were partially wrapped in bandages.
Bhim Bahadur Khatri, 35, a cook and a Sherpa, was preparing food in a meal tent when the avalanche struck.
‘‘We all rushed out to the open and the next moment a huge wall of snow just piled on me,’’ he said in a brief airport interview before being driven to a hospital. ‘‘I managed to dig out of what could easily have been my grave. I wiggled and used my hands as claws to dig as much as I could. I was suffocating, I could not breathe. But I knew I had to survive.’’
When he finally dug his way out, gulping in fresh air, he was surrounded by devastation. Part of the base camp village was gone.
‘‘I looked around and saw the tents all torn and crushed. Many people were injured,’’ he said. ‘‘I had lived but lost many of my friends.’’
The magnitude-7.8 quake struck at around noon Saturday — just over a year after the deadliest avalanche on record hit Everest, killing 16 Sherpa guides on April 18, 2014.
Witnesses said the avalanche began on Mount Pumori, a 7,000-meter (22,966-foot) -high mountain just a few kilometers (miles) from Everest, gathering strength as it headed toward base camp and the lower reaches of Everest’s climbing routes. Numerous climbers remained stranded Sunday on routes above base camp, but teams in contact by satellite telephones said no one was believed to be in danger or running short of supplies.
Azim Afif, the 27-year-old leader of a climbing team from University of Technology Malaysia, estimated that about 80 percent of the people at base camp had left by midafternoon Sunday.
He said that the critically injured had already been evacuated, and that temporary clinics had been set up for people with lesser injuries. Everest attracts a range of climbers, from barely skilled hobbyists to some of the world’s most experienced mountaineers, many of whom have extensive emergency training and come prepared with medical supplies. Those mountaineers, many on Everest to work as professional guides, almost certainly were able to treat many of the injured.
In an interview on the message service WhatsApp, Afif said that the dead were being respectfully wrapped, but that the ‘‘priority is for those injured.’’
Earlier in the day, Ang Tshering of the Nepal Mountaineering Association said 22 of the most seriously injured had already been taken by helicopter for treatment in the village of Pheriche, where the nearest medical facility is located. It wasn’t clear whether that number had risen by late Sunday.
Nepal was also hit Sunday by a series of aftershocks, triggering more avalanches in the mountains above base camp. None of those avalanches, though, were believed to have caused further injuries.
But each aftershock, Afif said, sent people in camp running from their tents to seek shelter behind large rocks.
Sullivan contributed from New Delhi. Associated Press journalist Karly Domb Sadof in Berlin contributed to this report.