At least nine climbers have died on K-2, the world's second highest peak, in one of mountaineering's worst tragedies.
The death toll could rise further, with four or more climbers still missing on the mountain. Those confirmed dead include three South Korean and two Nepalese climbers, along with Serbian, Norwegian, Dutch and French climbers, while Ger McDonnell from Ireland is among the missing.
Six are believed to have been killed by an ice avalanche, while reports suggested that other deaths may have been due to unrelated accidents.
The disaster struck at a steep gully known as the Bottleneck with an altitude of more than 8,000 metres. Part of a over-hanging slab of ice above the Bottleneck gave way and came hurtling down on the climbers and their ropes.
A sudden clearing after months of bad weather in the Karakoram mountain range in northern Pakistan, where K-2 is, meant that several expeditions rushed to take advantage. "Expeditions had been waiting at base camp for up to two months for good weather," said Rashid Ahmad, who runs Hushe, a tour company that had climbers on K-2 who survived the tragedy. "They had all started together, in one line. K-2 is more dangerous than Everest, due to the loose rocks and avalanches."
A total of 22 climbers, mostly foreigners, from eight different expeditions reached K-2's summit over the weekend. Most were on their way down the 8,600m (28,250 feet) slope when the avalanche occurred.
The previous deadliest day in the history of K-2, was on August 13, 1995, when six people, including British female climber Alison Hargreaves, fell or disappeared during a storm.
The ice fall left around a dozen climbers stranded at the Bottleneck, at an altitude known as the "Death Zone" because bodies begin degenerating due to lack of oxygen.
Some were able to make their way down and others were still descending last night. Several rescue parties have been sent up the mountain and helicopter teams are standing by.
Nazir Sabir, president of Pakistan's Alpine Club, said: "These are big mountains and are dangerous at any time. They take their toll every year. Mountaineering is a calculated risk."