Enlarge Pakistan Tourism Office via Reuters An ice avalanche on K-2, the world's second highest mountain, may have claimed several climbers' lives. ISLAMABAD, Pakistan (AP)  At least nine mountaineers are feared to have died on the world's second-highest mountain, K-2, including at least six who were struck by an avalanche as they were descending from the summit, officials said Sunday. Three other climbers reportedly died in separate incidents over the weekend on K-2 in northern Pakistan, which is regarded as more difficult to climb than Mount Everest, the world's highest peak. A total of 22 climbers, mostly foreigners, from eight different expeditions reached K-2's summit on Saturday. They were struck by an ice avalanche about 1,148 feet below the peak on their way down, said Nazir Sabir, whose Alpine Club of Pakistan organized a Serbian expedition on the mountain. He said seven people are feared to have died and three others were missing in the avalanche. However, Mohammed Akram, vice president of the Adventure Foundation of Pakistan, a nonprofit organization, said six climbers died when they were hit by the "ice cornice" crashing off an overhang, and that a South Korean climber had died a day earlier from an undetermined cause. Sabir initially reported that nine people had died in the avalanche, but later said two climbers — a Pakistani and a Serbian, whose expedition he helped organize — had fallen to their deaths a day before. It was not immediately possible to reconcile the differing tolls given by Akram and Sabir. A military-run helicopter service, Askari Aviation, which helps rescue climbers at high altitudes, had no information on any deaths on K-2. It said an Irish climber, who was not identified, was also missing on the mountain. Akram said five climbers of a separate Dutch-led expedition were missing. Agostino Da Polenza of Everest-K2-CNR, an Italian-based high-altitude scientific research group, confirmed to Sky Tg24 TV that nine are feared dead and four remained missing. K-2 is 28,250 feet high, about 785 feet less than Mount Everest. Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more