The statements of Steven Newton and Sarah Finch

Sarah Finch, 25, and boyfriend Steven Newton, 24, of Dartford, Kent, said they were unable to get out of the way of the snowfall and "blacked out" after it hit them.

The third survivor, climbing instructor Roger Wild, praised the rescue teams and said his thoughts were with the families of those who had died.

The BBC's Andrew Cassell: "The wall of snow hit them from behind"

The avalanche on the 4,000ft high Aonoch Mor, a mountain adjoining the UK's highest peak Ben Nevis, killed four of their friends, Emma Ray, 29; Paul Hopkins, 28; Matthew Lewis, 28, and Ian Edwards, 30.

Ms Finch, Mr Newton and Mr Wild were trapped under 3ft of snow, but suffered no serious injuries.

However, they are being kept in hospital for further observations due to complications caused by crush injuries.

It is the second scrape with death for Mr Newton who was reported missing at sea for 24 hours in 1990 while on a night navigation sailing exercise with the Scouts.

The boat he was in eventually washed ashore in Essex after losing its sails in a storm.

His father, Ted, said: "We were worried out of our minds - we never dreamt anything like this would happen again."

In a statement released from Belford Hospital, Fort William, Ms Finch and Mr Newton said that the first hour of their trip onto the mountain, part of a two-day Scouts winter climbing course, had been uneventful.

Roger Wild: Praised by rescuers

"We put our rucksacks down in a big pile," said Ms Finch. "Our ice axes were stuck in the ground and he [Mr Wild] asked us just to chat as he was going a little bit higher up to check out somewhere for us to do the ice axe work.

"He took a couple of paces away from us and the snow just came from behind us."

Mr Newton said: "It just came down towards us and we could not move. We did not have time to get out of the way."

Within seconds the three were covered in what they believe could have been another wave of snow.

Ms Finch added: "It just knocked us off our feet, and covered our heads. I tried to stand up once it was all around me.

"The next thing I remember is being stuck in a block of ice with just a little space to breathe."

Deceptive: Weather can change in minutes

Mr Newton, who is claustrophobic, said he began to panic and struggled to fight free from the snow.

He and his girlfriend said they were overjoyed when they realised they had been saved and described the mountain rescue team as "brilliant".

In a statement, Mr Wilde said: "My main thoughts at the moment are with the bereaved families.

"I am very pleased that two of the group have survived and would like to thank the rescue team and the medical services for their prompt and professional actions which undoubtedly saved our lives."

He also said the hospital staff had been "superb" and asked for "peace" for the survivors to give them time to recover from their injuries.

Earlier, rescuers and doctors said that they had been amazed that three of the party had survived when they were eventually found at 0120 GMT on Wednesday.

Terry Confield of Lochabar Mountain Rescue, which found the survivors, said: "I have never found anyone alive in an avalanche yet and I have been in the rescue service for 36 years. That speaks for itself."