Kathmandu, Jan 19 (IANS): Four South Koreans and three Nepali guides remain missing following an avalanche near the Annapurna mountain range, while over 150 domestic and foreign tourists have been rescued from in and around the area, officials said.

The incessant snowfall caused the avalanche near a popular trekking route in the Himalayan country. The area is close to the base camp for Annapurna, one of the highest peaks in the Himalayas.

"Four South Koreans and three Nepalis, guides and porters and who were separated from their nine-member group are still out of contact as over 150 Nepalis and foreigners rescued from around the area on Saturday alone," Bhim Gurung, chairman of ward No-11 of the Annapurna Rural Municipality, told Xinhua on Saturday evening.

Efforts to mobilize helicopters for the rescue operation were hampered by continued bad weather.

"But we could not land the helicopters at the main avalanche-hit area from where trekkers are missing," said Yogesh Sapkota, chief marketing officer at Simrik Air, which was involved in the evacuation on Saturday.

As his company rescued 80 to 100 trekkers, Sapkota said, there was almost no trekker left in Annapurna base camp area.

"Around 40 people have already arrived in capital Kathmandu while many reached the nearest city Pokhara," he added.

Despite rescue efforts on Saturday, helicopter companies and trekking agencies said that the situation of the seven people missing remained unknown.

"Search operation is underway but it has not been effective due to bad weather," Sirata Lama, general secretary of Trekking Agencies' Association of Nepal (TAAN), an umbrella organization of trekking companies present in the country, told Xinhua on Saturday evening.

Spring and autumn are regarded as the ideal season for trekking in Himalayas, however, many foreign trekkers opt to trek in winter for adventure and due to individual time availability, according to the trekking companies.