Two climbers from the United States and Switzerland have died on Mount Everest, becoming the first fatalities of this year’s season, expedition organisers in Nepal said Thursday.

“Two climbers passed away on Wednesday,” Mingma Sherpa of Seven Summit Treks told AFP.

The Swiss climber died near the summit after reaching the top and was suffering from exhaustion, said Chhang Dawa Sherpa from the same organisation.

“We sent two additional Sherpas with oxygen and foods, unfortunately Sherpas couldn’t save him,” he said on Instagram.

The American reached the Hillary Step but was helped back down after he suffered snow blindness and exhaustion, organisers said. He was able to reach Camp 4, but later died.

In recent seasons, Everest has seen a surge in the number of climbers, leading to overcrowding that has been blamed for multiple deaths.

To ease the crowding, Nepal’s tourism ministry announced rules capping the number of people who could summit the mountain per window of suitable weather.

The pandemic wiped out last year’s season, but Nepal has eased quarantine rules to attract more climbers despite the difficulties of treating them if they contract the virus.

The warmer weather that ushers in safer conditions for scaling Nepal’s dangerous, snow-capped peaks has coincided with a deadly second wave of Covid-19 infections.

Last week more than 30 sick climbers were evacuated from base camp although only two have been confirmed as having had coronavirus.