Mount Everest casualties reach 17 with unknown number still missing after devastating Nepal earthquake

A British Army team was on the mountain when the magnitude-7.8 quake struck

Mount Everest base camp after the avalanche (AP) (AP)

An avalanche on Mount Everest caused by the huge earthquake which hit Nepal has killed at least 17 people and left an unknown number injured or missing.

The avalanche struck between the mountain’s base camp and the notoriously treacherous area of collapsed ice and snow, known as Khumbu Icefall.

Survivors described huge pieces of rock and ice falling from the mountainside, which smashed into base camp.

Ministry officials estimated that at least 1,000 climbers, including about 400 foreigners, had been at base camp or on Everest when the initial earthquake struck.

The first rescue plane carrying injured people from the mountain arrived in Kathmandu on Sunday, just after a powerful magnitude-6.7 aftershock caused further avalanches on Everest. No further casualties have been reported.

Captain Tim Bradshaw, who is leading a British Army team that is attempting to scale the mountain, said that his tent began to “rock and move” as the earthquake hit.

“Then almost like thunder huge boulders started to break around us from the side of the mountain and roll down towards the bottom, towards base camp," he told Sky News.

“Everyone here is fine ... but we are on the other side of the mountain away from the Nepal side, quite away from the epicentre.”

At Everest camps 1 and 2, about 100 climbers and guides were unable to return to base camp because of the damage to a route through Khumbu Icefall, a rescue leader said.

Two British climbers, Alex Schneider and Sam Chappatte, who were on Everest at the time of the first avalanche blogged about the experience.

"The ground started shaking violently but before we could react Dan [a guide] was shouting 'Get out of your f*****g tents, grab your ice axes!'." the pair wrote.

"We staggered out to see an avalanche coming straight at us. A blast of wind knocked us down but we were able to get up and run to shelter behind some tents and anchor ourselves with our axes."

Romanian climber Alex Gavan tweeted there had been a "huge avalanche" and that "many, many" people were on the mountain at the time.

It is unknown if there are other British climbers on Everest. A spokeswoman from the Foreign and Commonwealth Office said: “We are aware of reports of an earthquake in Nepal. We are urgently looking into it.

"Our thoughts are with all those affected. Our Embassy staff stand ready to help any British nationals who may need assistance.”

AP