“I have seen 11 bodies brought to the base camp, we have been told to expect three more,” Lakpa Sherpa from the non-profit Himalayan Rescue Association told a news agency by telephone from Everest basecamp.
Meanwhile, an expert has termed this accident as the “most deadly” in mountain’s history.
The previous record was in 1996 when eight people from an expedition died in a tragedy immortalised in the best-selling book “Into Thin Air”, said Kathmandu-based Elizabeth Hawley, who runs the Himalayan Database and is regarded as the leading authority on Himalayan mountaineering.
The avalanche occurred at around 6:45 am (0100 GMT) at an altitude of about 5,800 metres (19,000 feet) in an area known as the “popcorn field”, which lies on the route into the treacherous Khumbu icefall, Sherpa said.
Tourism Ministry spokesman, Mohan Krishna Sapkota, said the climbers were all Nepalese and were preparing the route to the summit ahead of the summer climbing season which kicks off later this month.
“The sherpa guides were carrying up equipment and other necessities for climbers, when the disaster happened,” said Sapkota.
Another Tourism Ministry official said three rescue helicopters had been deployed to scour the site and airlift the injured to safety.
Hundreds of climbers, their guides and support guides had gathered at the base camp, gearing up for their final attempt to scale the 8,850-meter (29,035-foot) peak early next month when weather conditions get favourable. They have been setting up their camps at higher altitudes and guides fixing routes and ropes on the slopes ahead of the final ascend to the summit in May.
As soon as the avalanche hit, rescuers and fellow climbers rushed to help.
More than 300 people have died on Everest since the first successful summit by Sir Edmund Hillary and Tenzing Norgay in 1953.
Every summer, hundreds of climbers from around the world attempt to scale peaks in the Himalayas when weather conditions are at their best.
Nepal is home to eight of the world’s 14 peaks over 8,000 metres.
As concerns of overcrowding on the “roof of the world” have grown, Nepal had earlier announced several steps this year to better manage the flow of climbers, minimise congestion and speed up rescue operations. The preparations included the dispatch of officials and security personnel to the base camp located at 5,300 meters (17,380 feet), where they would stay throughout the spring climbing season that ends in May.
Nepal’s government also announced plans to double the number of climbing ropes on congested ice walls near the summit of Everest.