Excessive number of tourists create avalanche fears on Mount Everest

A guide said 'the vibrations caused by helicopters can crack ice blocks and snow packs on mountains'

A series of disasters have halted Everest expeditions for the last two years (Paula Bronstein/Getty Images)

Excessive sightseeing helicopter flights over the upper reaches of Mount Everest are causing avalanche concerns.

A series of disasters have halted Everest expeditions for the last two years.

In 2014, sixteen Sherpas were killed by an avalanche that swept down a climbing route. Last year, at least 18 climbers died at Base Camp after an earthquake triggerd an avalanche.

While tourist flights are not allowed to fly above Base Camp, which is at an altitude of 5,364 metres (17,000ft), a BBC investigation found tourist companies fly over the Khumbu Icefall.

An aerial photograph of the Khumbu Icefall along Everest's West Shoulder (Paula Bronstein/Getty Images)

Concerned mountain guides told the BBC they fear "that the vibrations caused by helicopters can crack ice blocks and snow packs on mountains overlooking the Khumbu Icefall".

"Pasang Kaji Sherpa, a mountain guide with a military expedition team now on Everest, said: "There is a deep-seated fear among Sherpa porters that they may be hit by avalanches this year as well and these helicopters are increasing fears."

However, airline officials insist there is no danger, as their helicopters fly 2,340 feet above the ground and maintain at least 1km distance from the mountains.

The Civil Aviation Authority of Nepal (CAAN) has since warned airlines not to conduct flights over the Khumbu Icefall.