At least 14 people are missing after an avalanche struck the base camp of the 7,126-metre (23,379-foot) Himlung Himal in Nepal's Manang district, with severe weather hampering efforts to reach the mountain, local officials and expedition organisers said.

The number of missing people initially stood at 10 but later increased to 14 as expedition organisers established that additional members of the team could not be contacted, according to the Kathmandu Post. All those reported missing are Nepali expedition personnel, including Sherpas and support staff. No foreign climbers had yet arrived at the mountain.

The avalanche struck in the Nar Phu region early Sunday after several days of heavy snowfall and persistent rain. The Nepali crew had been sent ahead of foreign clients to prepare the base camp, manage the route and fix climbing ropes. The foreign climbers were expected to arrive in the following days.

Bibhuti Chand Thakur, founder of Himalayan Holidays Trekking, said the expedition initially reported that eight members could not be contacted before the number rose to 14.

Helicopters have been placed on standby in Kathmandu and Pokhara, while authorities and private operators are coordinating a possible rescue operation. However, deteriorating weather has so far prevented aircraft from reaching the mountain.

Nepal's Department of Tourism is coordinating with relevant agencies and is also considering the use of a Nepali Army helicopter, officials said. Rescue teams on the ground have likewise been unable to reach the area because of the difficult conditions.

Ram Krishna Lamichhane, director general of the Department of Tourism, said authorities were closely monitoring the situation and gathering information on those missing.

The avalanche also buried tents at the base camp, according to expedition operators. Two of the missing personnel were associated with Imagine Nepal, while others were working with Himalayan Holidays.

The disaster came after authorities issued warnings about deteriorating weather in Nepal's mountain regions.

A weather system over the Bay of Bengal has brought heavy snowfall to high-altitude areas and persistent rainfall to lower elevations. The Department of Tourism had advised trekkers, mountaineers and support personnel to suspend activities between Sept. 25 and 27 because of the risk of heavy rain, thunderstorms, strong winds, snowfall, landslides and floods.

The worsening conditions have also disrupted other mountaineering expeditions. Heavy snowfall forced climbers on Manaslu to abandon or suspend some attempts, while trekking activities in the Dhaulagiri region were also disrupted.

The Himlung Himal avalanche comes as Nepal deals with severe weather and a series of floods and landslides across the country.

In Palpa district, at least one person was killed and two others were reported missing after a landslide, while flooding of the Kaligandaki River in neighboring Parbat district washed away about 80 houses, according to local reports.

Nepal is also still dealing with the aftermath of devastating floods and landslides in August. The disasters killed more than 1,400 people and left thousands missing, according to reports cited by international news agencies.

Himlung Himal, located near Nepal's border with Tibet, is a popular high-altitude climbing destination. Nepal's autumn mountaineering season attracts climbers from around the world and provides an important source of income for the country's tourism industry.

For now, rescue teams remain on standby, with operations dependent on a break in the weather that would allow helicopters to reach the avalanche-hit base camp. (ILKHA)