Nepal’s tourism authority has denied claims the rising death toll on Mount Everest is because of overcrowding – amid reports up to 10 climbers have already died on the mountain this season.

British climber Robin Haynes Fisher, 44, died on Saturday, minutes after reaching Everest’s 8848-metre summit.

Murari Sharma of Everest Pariwar Treks in Kathmandu said Mr Fisher died at 8700 metres.

“He had descended about 150 metres below the summit when he suddenly collapsed. His Sherpa guide tried to rescue him, but he had already died,” Mr Sharma said.

On Friday, 56-year-old Irishman Kevin Hynes died in his tent at 7000 metres after turning back before reaching the summit, British climbing company 360 Expeditions said in a statement.

That same day, Nepalese guide Dhurba Bista, 33, died at the base camp after being airlifted from a higher camp following illness, according to his employer, Anil Bhattarai of Himalayan Ecstasy Treks.

Three Indians – two women and one man – died this week during their descent after scaling the peak, as hundreds of climbers pushed for the summit while taking advantage of this week’s weather windows.

A local tour organiser told AFP that one of the Indian climbers, Nihal Ashpak Bhagwan, died of exhaustion after being “stuck in traffic for more than 12 hours”.

Last Wednesday, an American climber, 54-year-old Donald Cash died after falling ill with altitude sickness. His death was reported as an incredible picture started to circulate on social media of a lengthy queue of climbers waiting to reach the summit of the world’s highest peak.

Hundreds of climbers try to climb Mount Everest and other Himalayan peaks during the spring climbing season.

Babu Sherpa, the managing director of Peak Promotion, said overcrowding had congested the route from Camp IV to the top of Everest.

“There were only short weather windows and everyone was trying to climb at once,” he said.

But the director-general of Nepal’s tourism authority, Dandu Raj Ghimire said other factors, including adverse weather, had also contributed to this year’s death toll.

Mr Ghimire said 381 people had climbed Everest this spring. But, because periods of fine weather had been limited, the traffic on the various routes had been “higher than expected”.

In his statement, Mr Ghimire put the current death toll at eight, although 10 people have been reported dead or missing.

They also include Indian climber, Anjali Kulkarni, who died during her descent, and an Austrian climber who died on the Tibetan side of the mountain.

“Due to the huge traffic yesterday and the delay in being able to return back, she couldn’t maintain her energy,” tour group manager Phupden Sherpa said of Ms Kulkarni, 54, who collapsed while returning from the summit.

Seamus Lawless, another Irish climber who went missing on May 16, is presumed dead on the mountain.

Mr Ghimire offered “heartfelt condolences to those who’ve passed away and prayers to those who are still missing”.

“Mountaineering in the Himalayas is in itself an adventurous, complex and sensitive issue requiring full awareness yet tragic accidents are unavoidable,” he said.

Five climbers died on Everest last year.

-with agencies