The climbers had hoped to be the first to reach the main peak and two lower peaks of 7,538-metre Kula Kangri. Bhutanese regard the mountain as the kingdom's tallest peak, although others say it lies in Tibet.

The victims included cameraman Susumu Nakamura, 62, who was Japan's first alpinist to reach the North and South Poles and Mount Everest. He was famous in Japan for broadcasting live from the top of Everest in 1988.

The other dead were Mr Yoshinobu Kato, 32, and Mr Satoshi Arimura, 27, expedition leader Mr Kazuhiro Takahashi said.

'I'm extremely shocked. They were sufficiently prepared and experienced,' Mr Takahashi told AFP by telephone from the mountain area.

'It's very hard to predict avalanches. Although I'm sure the three tried to forecast them, avalanches can occur very suddenly. But I think global warming, which melts ice, may have played a role,' he said.

The victims had separated to go ahead of the other four members of the expedition, which began the ascent on Sept 20.

After losing contact with the three early Wednesday, Mr Takahashi and other members went on a search and found their bodies buried in snow at an altitude of 6,000 metres, he said.

Just one day before their deaths, the sky was clear and sunny, with Mr Takahashi posting pictures of the gleaming white peaks on his blog.

An earlier post showed expedition members enjoying a Japanese-style omelette during the climb.

'I had a bad feeling when I saw him off at the airport,' the father of Mr Arimura, a graduate student at prestigious Waseda University, told public broadcaster NHK. -- AFP