Two Indian climbers have gone missing on Mount Everest just days after two others died from apparent altitude sickness.
Paresh Nath and Goutam Ghosh have been missing since Saturday and were last seen near the Everest summit, the expedition organiser said.
Wangchu Sherpa, from the Trekking Camp Nepal agency in Kathmandu said two of their companions who fell sick were being helped down the mountain.
Several Sherpa guides carried one sick climber from the highest camp, at nearly 8,000 meters (26,420ft) above sea level to Camp 2 at 6,400 metres (21,000ft) where attempts were made to pick her up with a helicopter.
Another member of the agency, Pemba Sherpa, identified her as Seema Goshwami of India.
He said she had frostbite on her hands and feet and was unable to move.
"It took a big and risky effort, but we were able to save her," he said.
Another climber, an Iranian identified only as S.Hadi, has already been brought down and is recovering in a hospital in Kathmandu.
Around 30 climbers have developed frostbite or altitude sickness near the summit in recent days.
It comes after two climbers on a separate expedition were the first deaths on the mountain this year following two years of low activity due to two fatal avalanches and the major earthquake which struck last year.
The climbers have been named as Dutch mountaineer Eric Arnold, 36, and Australian finance lecturer Maria Strydom, 34.
Mr Arnold is believed to have had enough bottled oxygen and climbing partners but complained of getting weak during the team’s descent and died on Friday night near South Col before being able to reach lower altitude.
Hours later, Dr Strydom showed signs of altitude sickness and died on Saturday afternoon.
It is currently undecided whether their bodies will be brought down from the high altitude as it will depend on team and family members.
Pasang Phurba of the Seven Summits trekking agency said it requires eight sherpas to carry bodies down the mountain because they become frozen and heavier than normal.
Fair weather has meant nearly 400 climbers have reached the summit from Nepal in the last two weeks but altitude, harsh terrain and sudden changes in the weather can cause problems at any point.
Mr Arnold, who had finally reached the top of the mountain on his fifth try, told the Dutch broadcaster RTV Rjnmond last year the majority of accidents happened when someone is on the way down.
He said: "Two-thirds of the accidents happen on the way down.
"If you get euphoric and think 'I have reached my goal,' the most dangerous part is still ahead of you."
Additional reporting by AP
