Pakistan Army rescued US mountaineer Robert Jackson from K-2 base camp, airlifting him to Skardu for treatment.
The 38-year-old was part of a 27-member team on an expedition to summit K-2, having arrived in Pakistan on June 16.
“He suffered altitude sickness enroute to K-2 and was brought to Skardu through army aviation helicopters,” an Inter Services Public Relations statement read.
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A total of five mountaineering teams have reached K-2 base camp so far. Among them is South African-born Swiss explorer and adventurer Mike Horn, who aims to ski down K-2 after summit.
However, most of the teams have decided to move their acclimatization process to neighbouring Broad Peak (8,051m) owing to a number of avalanches on K-2. Avalanches on the mountain have increased following last week's earthquake in China.
Samina Baig, the first Pakistani woman and the third Pakistani to climb Mount Everest, has also reached base camp along with her brother Mirza Ali with aim of scaling K-2.
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In April, Baig was one of the fortunate ones who survived the deadly avalanche on Mount Everest following the earthquake which tore at the very heart of Nepal recently.