US mountaineer Hilaree Nelson missing on Mount Manaslu in Nepal

Rescuers have been searching for a famed US mountaineer who has gone missing on the world's eight-highest mountain in Nepal.

Hilaree Nelson, 49, was skiing down the 8,163m mountain with her partner Jim Morrison on Tuesday when she fell off Mount Manaslu, according to organisers of the expedition.

Jiban Ghimire of the Shangri-La Nepal Trek, said a helicopter was sent to hover over the mountain to find any signs of the missing climber.

Ms Nelson and her partner are extreme skiers who summited Mount Lhotse, the world's fourth-highest peak, in 2018.

Ms Nelson's sponsor, The North Face, said they are "in touch with Hilaree's family" and describe her on their website as "the most prolific ski mountaineer of her generation" and a mother-of-two.

On Monday, an avalanche at a lower elevation on Mount Manaslu swept several climbers and killed a Nepali guide and injured other climbers.

All of the climbers caught in the avalanche Monday were accounted for, with some of the injured flown to Kathmandu and treated at hospitals for their injuries.

After landing from the helicopter, one of the avalanche survivors, Phurte Sherpa, said: "I am not sure about the whereabouts of the missing climber but her husband was with us during the search today. We made two helicopter rescue attempts, but we were unable to find her."

Mr Sherpa, said there were about 13-14 people who were swept by the avalanche.

Hundreds of climbers and their local guides are on the mountain attempting to reach the summit during Nepal's autumn climbing season.

Nepal's government has issued permits to 504 climbers to attempt to scale high mountain peaks during the autumn season. Most of them are on Mount Manaslu.