Rescue helicopters have landed at Everest base camp, where a deadly avalanche triggered by the Nepal earthquake has killed at least 17 people, and left hundreds of climbers trapped on the mountain, according to reports.

Previous helicopter missions had succeeded in airlifting 22 of the most seriously injured people at the camp to Pheriche village, the nearest medical facility. However, bad weather and communications have been hampering subsequent attempts at helicopter sorties, Ang Tshering of the Nepal Mountaineering Association, told the Associated Press.

An Indian army spokesman told Reuters earlier that a climbing team found 18 bodies on Saturday in the first hours after the quake, but agencies but the death toll at 17 at the time of publication.

In addition to the dead, at least 61 people at the camp were injured in the avalanche. The death toll from the earthquake, which affected Nepal, parts of India and Tibet has passed 1,800 people, and is expected to rise in the coming days.

At least 31 staff and climbing clients -- including two from the United States, five from New Zealand and one each from Australia, Italy and Iceland -- were safe but stranded at Camp One, further up the mountain.

"The first stage and the first priority is to get them down to base camp. We don't know if it's going to be possible to get them down and out through the Khumbu Icefall or whether we will need to chopper them out," Steve Moffat, a mountain guide and operations coordinator for New Zealand-based Adventure Consultants, told Reuters.

Experienced mountaineers said panic erupted at base camp, which has been "severely damaged", while one described the avalanche as "huge", AFP reported.

"Huge disaster. Helped searched and rescued victims through huge debris area. Many dead. Much more badly injured. More to die if not heli asap," Romanian climber Alex Gavan  tweeted from base camp.