Indian mountaineer Subhash Paul died on Mount Everest on Sunday, after four Indians went missing while climbing the world’s tallest peak. Two of Paul’s teammates are still missing. Paul’s death came after two other mountaineers died on Everest over the weekend, BBC reported. All three succumbed to altitude sickness. Reports said that dozens of climbers have recently become ill or developed frostbite near the summit.

Last week, a Nepali guide died while climbing Mount Lhotse, and an Indian mountaineer died during his descent from Mount Dhaulagiri, AFP reported. Around 289 permits were issued to foreigners for the brief climbing season in Nepal, which usually runs from mid-April to the end of May. Last year, the trekking season was hit after the devastating Nepal earthquake.