Climbers who survived an avalanche in the dark on one of the world's deadliest peaks told Tuesday of their horror as breaking dawn revealed the bodies of their companions littering the mountain.

Nine people - four French climbers, a Spaniard, a German and a Nepali guide - were killed while two Frenchmen and a Canadian man are missing, also feared dead with the search ending its third day.

Italian climber Christian Gobbi (42) said he and his friend, Silvio Mondinelli (54), had woken and were talking when suddenly their voices were drowned out by a giant roar.

The avalanche then swept their tent on Nepal's Manaslu peak down the slope.

"It was only a few seconds and we did not know what had happened, but we had slid more than 200 metres (650 feet). Then it stopped," he told AFP from a hotel in Kathmandu.

Gobbi and Mondinelli ventured outside their torn tent and couldn't see anything in the pitch black.

But as the sun came up, they discovered the body of the Nepali guide who had led on the hazardous trek up and their friend, Italian Alberto Mariano, among broken tents, scattered belongings and the bodies of the other climbers.

"We were terrified - we didn't know what to do," said Mondinelli.

The group of more than 20 at the camp were hit by a wall of snow in their tents near the peak of the 8156-metre (26 759-foot) Manaslu in the early hours of Sunday.

"There was one American, who was screaming and asking for help, but we couldn't do anything. We checked to find out who was alive and who had died. I alone saw seven dead bodies," said Gobbi.

Rescuers managed to pluck 13 people alive from the avalanche, described by survivors as looking like a "war zone", with several flown to hospitals by rescue helicopters.