Six climbers fall to their deaths scaling Mount Rainier in Washington state, US

Six climbers have been killed in a 1,010-metre fall on the steep north slope of Mount Rainier in the US state of Washington.

It is the worst disaster on the mountain in more than three decades.

Searchers found tents and clothes, mixed with rock and ice, among debris along the Carbon Glacier at 2,900 metres. the National Park Service said. The group's climbing route, to Liberty Peak, is prone to slides and considered relatively difficult.

The six climbers - two guides and four clients from Seattle-based Alpine Ascents International - were last heard from at 6pm on Wednesday by satellite phone. At that time the party was at 3,900 metres with plans to camp overnight. When they failed to return on Friday as planned, the company contacted park rangers. Alpine Ascents is the company that lost five Sherpas at Mount Everest this spring.

At Mount Rainier, the search on Saturday by helicopters and climbing rangers was suspended four hours before dark.

"They feel there is no chance of survival at this point," said Fawn Bauer, a spokeswoman for the National Park Service.

This is the worst climbing disaster on Mount Rainier since June 21, 1981, when 11 climbers were killed by an avalanche on Ingraham Glacier, on the southeast side of the mountain.