Their decision came a week after a large chunk of ice fell off the face of the mountain, killing 11 climbers.

Three others survived and were badly frost bitten. They were airlifted by helicopter from base camp over the last three days.

Dr Goh, 42, said the decision was taken with great reluctance and heavy hearts.

'The mountain is so near, yet so far. The tents and equipment are all up there ready for us. But with 11 climbers killed when the weather was perfect, it was just too shocking for words,' he said.

About three-quarters of the mountaineers at the base camp have left for home.

Only two other teams remain at base camp ? two Rumanian climbers with two Sherpas and two Pakistani high-altitude porters; and three Americans who came without Sherpas or porters.

This makes manpower at base camp 'very thin'.

In a statement to the media, Ms Lulin Reutens, the expedition spokesman, said: 'If there should be an accident, there would not be enough people to mount a rescue.'

Since Saturday's tragedy, the duo had been helping in the evacuation of the three injured climbers.

They expect to start trekking from base camp next Friday, arriving in Islamabad 10 days later on Aug 25.