More than 900 climbers to head up the world’s highest peak four years after at least four deaths were blamed on overcrowding.

Nepal has issued a record 454 permits to climb Mount Everest this spring, officials say, four years after at least four deaths on the world’s highest peak were blamed on overcrowding.

“This is the highest number of permits the department has issued to summit Mount Everest,” Bigyan Koirala from the tourism department told the AFP news agency on Monday, adding that the number could rise further.

Because most of these mountaineers will attempt to summit Everest with the help of a Nepali guide, more than 900 climbers will be heading for the summit in the next few weeks during the peak climbing season from April to May.

This could cause heavy traffic and bottlenecks en route to the summit if there is a shorter window to reach it because of unfavourable weather.

In 2019, a massive queue on Everest forced teams to wait hours in freezing temperatures to make the summit. The delay lowered climbers’ depleted oxygen levels, leading to sickness and exhaustion.

At least four of 11 deaths that year were blamed on overcrowding.

The highest number of climbers receiving permits this season were from China (96), followed by the United States (87).

Ang Tshering Sherpa, former president of the Nepal Mountaineering Association, told AFP the high numbers this season were the result of many climbers being unable to travel to Nepal in recent years due to the pandemic.

In addition, new rules on the Chinese side of Everest requiring climbers to have scaled one other 8,000-metre peak first were sending more Chinese to Nepal.

A team of professional mountaineers is currently preparing the route up to Everest and has already fixed ropes up to Camp IV at 7,924 metres (25,997 feet).

Sherpa said recent snowfall has heightened the risk of avalanches on the mountain.

“Normally, it’s during the winter when there should have been a snowfall, but there was snowfall recently during the spring,” Sherpa said. “The fresh snow remains soft, which increases the risk of avalanche.”

Three Nepali climbers went missing on Everest while crossing the treacherous Khumbu Icefall on April 12. Authorities called off the rescue after concluding that it was not possible to retrieve their bodies from a deep crevasse.

Nepal is home to eight of the world’s 10 highest peaks, and foreign climbers who flock to its mountains are a major source of revenue for the country.

The government charges $11,000 per foreign climber and has collected $4.86m from the Everest permits.