An American climber died on the descent from the summit of Mount Everest on Monday, a Nepalese official said, and an Australian climber has been rescued by Tibetan alpine specialists after being found unconscious on the northern slopes of the peak.

The American’s death took the number of dead or missing mountaineers on the Nepalese side of the world’s highest mountain in the current climbing season to nine.

Christopher John Kulish, 61, scaled the 29,035ft peak from the normal south-east ridge route in the morning but died suddenly at the south col after descending from the summit, said Mira Acharya, a Nepal tourism department official.

The authorities did not say where he was from in the US. The cause of his death was unclear.

Most deaths on Everest this year have been attributed to exhaustion and tiredness, exacerbated because a crowded route to and from the summit has led to delays. The short climbing season ends this month.

The route, also called the south col route, was pioneered by New Zealander Sir Edmund Hillary and Nepalese Sherpa Tenzing Norgay in 1953.

About 5,000 people have scaled the Everest summit so far and about 300 have died on its slopes.

Two climbers are also confirmed dead on the Tibetan side in this climbing season.

A record 381 climbers had been permitted to scale the summit from the Nepalese side. About 130 others were tackling Everest from the mountain’s northern side in Tibet.

The unnamed Australian man was experiencing health problems at an altitude of 7,500m when he was discovered on Wednesday by a four-person mountaineering crew returning from repair work, the China Daily reported.

The team used a riding yak to help move the climber to a base camp. He was taken to a hospital in Kathmandu where his condition has since improved.

Australia’s Department of Foreign Affairs and Trade is providing consular assistance to the man.