KATHMANDU (Reuters) - Seven trekkers, including four South Koreans, went missing in Nepal’s northwest Himalayan region after an avalanche hit their trail, local police and hiking officials said on Saturday.

The area where the avalanche struck the group, which also included three local guides, is estimated to be about 150 km (93.21 miles) northwest of Nepali capital Kathmandu, according to the officials. The avalanche was triggered by heavy rain and snowfall, they said.

“Four of our Korean clients, who were trekking in the Annapurna region are not in contact and are missing since an avalanche struck them on Friday,” Sandesh Pandey, who runs the tour company which organised the hike, told Reuters.

Mount Annapurna, in northwest Nepal, is the world’s tenth highest mountain at 8,091 metres (26,545 feet) and its base camp is popular with thousands of trekkers who visit annually.

The three Nepali guides are also not reachable, said Mira Acharya, a tourism department official in Kathmandu.

Four helicopters have been deployed for the search and rescue mission with police and local volunteers also looking for the trekkers, Acharya said, adding, however, that rough weather conditions were making the operation difficult.

The incident comes as the annual trekking season in Nepal, home to eight of the world’s 14 highest mountain peaks including Mount Everest, is drawing to a close.

It could potentially dampen the mood for the Himalayan nation’s tourism industry, yet to recover from a devastating earthquake which killed nearly 9,000 people in 2015 including 18 climbers and their guides at the base camp of Mount Everest.

Cash-strapped Nepal earns 4% of GDP through income from tourists.

About 8% of the nearly 1.1 million tourists who visited the country in 2019 went hiking or mountain climbing, according to official estimates.

Separately, four rescue helicopters on Saturday evacuated nearly 200 trekkers in the Annapurna region – about 140 of them foreigners - to safer locations, police said. Their nationalities are not yet known.