Three climbers have died on Mount Everest and another is missing in a busy and tragic weekend on the world's highest mountain, officials and expedition organisers said.
An American climber died near the summit and an Indian climber is missing after heading down from the top following a successful ascent, expedition organisers said.
Roland Yearwood, 50, from Georgiana, Alabama, died on Sunday but details were not immediately known, said Murari Sharma of the Everest Parivar Expedition agency, based in Kathmandu, Nepal's capital.
Indian climber Ravi Kumar fell sick on his way down from the summit on Saturday and did not make it to the nearest camp, though his accompanying Nepalese Sherpa guide did reach camp, said Thupden Sherpa of Arun Treks and Expedition.
The guide was sick but had managed to drag himself to the camp at South Col, located at 26,247ft, he said, adding that the guide had frostbite and was receiving oxygen.
Kumar and his guide reached the 29,035ft-high summit about 1.30pm local time on Saturday, which is considered late, and not many climbers were around when they were returning back.
Three Sherpa rescuers were flown by helicopter to Camp 2, from where they were climbing up the mountain to help search for the missing climber.
A Slovak climber Vladimir Strba, 50, also died on Everest on Sunday, Tourism Ministry official Gyanendra Shrestha said. His body was brought the South Col camp.
Australian climber Francesco Enrico Marchetti, 54, from Queensland, died on the Chinese side of Everest, according to the Himalayan Times newspaper. Other details were not available.
The number of climbers who have died on Everest during the current spring climbing season, which began in March and runs through this month, has now reached five with one missing.
More climbers are also expected to attempt to reach the peak on Monday.
The Nepalese Tourism Department issued a record 371 permits this year to people to scale the mountain. The increased number of climbers this year is likely because many people were unable to climb in 2014 and 2015, when deadly avalanches disrupted the climbing seasons.
Climbers who had permits for the 2014 season were allowed to receive a free replacement permit until 2019, while climbers with 2015 permits were given only until this year.