Death toll from Mount Everest avalanche triggered by Nepal earthquake climbs to 17

Climbers on the world's highest mountain have pleaded for help after a massive earthquake triggered an avalanche at Everest base camp, killing at least 17 people and injuring at least 61 others.

Google executive Daniel Fredinburg, based in California, had been climbing the mountain with a British tour company and is among those confirmed dead.

His family confirmed he had died of a "major head injury" after the devastating avalanche.

READ MORE: Death toll from Nepal earthquake climbs

"We appreciate all of the love that has been sent our way thus far and know his soul and his spirit will live on in so many of us," his sister Megan wrote on Instagram.

"All our love and thanks to those who shared this life with our favorite hilarious strong willed man."

Adelaide man Zachary Sheridan, 20, is missing.

He is the younger brother of Australian television actor Hugh Sheridan.

Toowoomba teen Alyssa Azar, 18, aiming to be the youngest Australian to climb the mountain, is safe and well.

Base camp was crowded with foreign mountaineers and their sherpa teams at the start at the climbing season when the avalanche hit, destroying camps and sending slabs of ice crashing in what was described as a "huge disaster".

Several helicopters have landed at Mount Everest base camp to rescue victims of an avalanche that has killed at least 17 people.

"People being stretchered out as choppers land - half a dozen this morning," AFP's Nepal bureau chief Ammu Kannampilly said in a text message.

Ang Tshering of the Nepal Mountaineering Association said today 22 of the seriously injured have been taken by helicopter to Pheriche village, the nearest medical facility.

Guides and triggered an unprecedented shut-down of the 8848m peak.

Some climbers are returning this year after being forced to abandon their attempt on the summit last April during the chaos and recriminations that followed the deadliest avalanche then to ever hit the mountain.