Kathmandu, Jan 20 (IANS): Four South Koreans and three Nepali guides were still missing following an avalanche near the Annapurna mountain range, with heavy snowfall in the region hampering search operations, it was reported on Monday.

Incessant snowfall caused the avalanche on January 17 near a popular trekking route close to the base camp for Annapurna, one of the highest peaks in the Himalayas.

Four Chinese nationals, who went missing while trekking along the Annapurna Trekking Route, were found safe, The Himalayan Times quoted officials from the Annapurna Conservation Area Project, as saying on Sunday.

Meanwhile, a senior police official said a search operation was underway to locate the missing seven persons suspected to be stranded in the Hing Ku cave between the Himalaya and Deurali.

"It is tough to reach the site due to snow. But, the police have reached there and started a search operation," the official said, adding: "They found nothing but some pieces of plastic."

A joint team of members from Century Youth Club, local traders, Trekking Agencies' Association of Nepal, Western Regional Association Pokhara and Union of Trekking Travels Rafting Workers Nepal have also reached the incident site for the search operation.

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.