Everest reopened last August after a deadly earthquake halted 2015 climbing season
Three climbers have died while trying to climb Mount Everest at the weekend, with another 30 falling ill.
Among the fatalities was a dutchman Eric Arnold, and Indian climber Subhash Paul.
Arnold was able to reach the summit - tweeting his success - but apparently died on Friday on the way down, despite having plenty of bottled oxygen.
Paul died overnight on Sunday as he was being helped down the 8,850 metre-high mountain by Sherpa guides.
Two other Indian members of his team - Paresh Nath and Goutam Ghosh - are still missing.
The third fatality was lecturer Maria Strydom from Melbourne in Australia.
Dr Strydom was an experienced mountaineer who had previously reached the summits of Argentina's Aconcagua and Mount Kilimanjaro.
She was attempting to mount the highest seven peaks on each of the seven continents in order to disprove claims that people who consume no animal products struggle with extreme activities.
Dr Strydom told the website of Monash University, where she works: "It seems that people have this warped idea of vegans being malnourished and weak.
"By climbing the seven summits we want to prove that vegans can do anything and more."
Sky News Australia said her family were devastated to have found out she had died by Googling her name.
Her husband, Robert Gropel was among those who fell ill on the mountain and had to be airlifted off.
The majority of those who have fallen sick have developed frostbite or fallen ill with altitude sickness near the summit, one expedition organiser said.
Everest reopened last August following two devastating years where 18 people were killed during Nepal's earthquake and 16 Sherpas died in 2014.
Favourable weather has allowed nearly 400 climbers to reach the summit from Nepal since 11 May, but the altitude, weather and harsh terrain can cause problems at any time.