KARACHI, Pakistan — Some climbers call it “the savage mountain.” K2 stands as the world’s second-tallest summit, after Mount Everest, and some climbers consider it even more perilous. Only last month did one group become the first to successfully scale it during winter, braving dangerously thin air and temperatures that can plunge past minus 70 degrees Fahrenheit.
On Monday, rescuers and mountaineers underscored the dangers of climbing K2 in winter after the authorities in Pakistan said that three climbers had been missing since Friday and that hopes of finding them alive were evaporating. The missing climbers were Muhammad Ali Sadpara, a 45-year-old from Pakistan; John Snorri, 47, from Iceland; and Juan Pablo Mohr, a 33-year-old Chilean.
The authorities said that they would continue the search on Tuesday after halting operations briefly on Monday because of poor visibility. But officials and some family members expressed little hope that the three would be found alive.
“There is no hope for anyone to survive at 8,000 meters after three days,” said Sajid Ali Sadpara, the son of Mr. Sadpara. The younger Mr. Sadpara had been part of the expedition but aborted his ascent at an altitude of 8,200 meters after his oxygen pipe started leaking. “Now the search operation should continue to recover the bodies,” he added.
The trio was making its second attempt to scale the summit since December. The three were last seen on Friday, around noon, at a narrow couloir called Bottleneck, the precipitous climb just 300 meters from the peak of K2.
K2, in the Karakoram range in northern Pakistan, near the border with China, is 8,611 meters — that’s more than five miles — above sea level. For decades, climbers from across the world have regarded scaling K2 from November to the end of February as one of the most daunting challenges in mountaineering.
Many who have tried have lost their lives. In 2008, 11 lives were lost, while 13 climbers died over a two-week span in 1986, one of the worst disasters in mountaineering history. Mountaineering experts say climbers face a lack of oxygen, snow blindness and frostbite.
This winter has been especially deadly. Last month, two climbers died after either falling down a crevasse while descending or trying to scale nearby peaks in preparation for K2.
A 42-year-old Bulgarian alpinist, Atanas Skatov, was found dead on Friday by a Pakistani Army helicopter on K2 after reportedly falling at about 7,400 meters.
In January, a Spanish climber, Sergi Mingote, fell to his death while descending the mountain. Alex Goldfarb, a Russian-American professor from Harvard University, also lost his life in the same month on a nearby mountain during an acclimatizing mission.
Still, climbers continue their attempts. Last month, a Nepali mountain-climbing team become the first to reach the peak of K2 during winter.
On Monday, despite harsh weather, Pakistani military helicopters continued an aerial search. International winter expedition experts based in Pakistan and several Pakistani mountaineering experts continued their search mission on the ground.
Mr. Sadpara, the son of the Pakistani climber, said the expedition team had been trying to reach the summit of K2 since Dec. 12. They began their second attempt on Thursday, he said.
The Pakistani foreign minister, Shah Mahmood Qureshi, after speaking to his Icelandic counterpart, Gudlaugur Thor Thordarson, said the government was making every effort, including continuing the aerial search, to trace the three missing mountaineers.
“We are praying for their safe recovery,” Mr. Qureshi said.
Karrar Haidri, an official at the Alpine Club of Pakistan, a private organization that promotes mountaineering in the country, said that there had been more than 360 successful climbs of K2 and 86 deaths since 1954. Causes of deaths included falling during descent, avalanche and bad weather, he added.
Mr. Haidri said that the base camp stopped receiving a signal from the three climbers after they reached 8,000 meters and that it was unclear if they had reached the summit.
“We can only hope for a miracle for their survival,” he said.
Zia ur-Rehman reported from Karachi, Pakistan, and Sameer Yasir from Srinagar, Kashmir.
