Helicopters airlifted injured climbers off Mount Qomolangma on Sunday after an avalanche killed at least 18 people, including one Chinese national, when a big aftershock hit the world's highest peak.

The first group of survivors from the earthquake-triggered avalanche that swept through the Qomolangma base camp were flown to Katmandu and taken to hospitals. None appeared to have life-threatening injuries.

At least six helicopters landed at base camp in Nepal, Agence France-Presse's Kathmandu bureau chief Ammu Kannampilly reported after weather conditions improved overnight.