Six people, including four South Koreans, remain missing in Nepal’s northwestern Himalayan region after an avalanche hit the area on Friday, Seoul’s Foreign Ministry said Sunday. 

The Nepali authorities said they have mobilized an additional six to 10 specialized police officers for a search mission that is underway. But heavy snowfall and rough weather conditions are making the search difficult.

Three search teams consisting of 13 locals who are familiar with the terrain and seven police officers have already conducted a land and air reconnaissance, but could not find the missing trekkers.

The incident occurred Friday at about 10:30-11 a.m. (local time) when the avalanche swept the Deuralri area, at an altitude of 3,230 meters near a base camp in the Annapurna region, following heavy snowfall.

Four Koreans -- two women, one in her 30s and one in her 50s, and two men in their 50s -- are all teachers from South Chungcheong Province. The other two people who went missing are Nepali guides.

The missing trekkers are part of the 11-teacher team taking part in a volunteer teaching program at schools in Kathmandu from Jan. 13-25.

Of the 11 teachers, nine went trekking on Annapurna, one of the highest mountains in the Himalayas, for the weekend and the other two stayed behind for health reasons. Five of the trekkers who were caught in the avalanche were rescued and are safe.

“I, along with the South Korean people, earnestly pray for the speedy rescue of the missing teachers and local guides at Annapurna. With the Seollal (Lunar New Year) holiday a week away, I am anxious, thinking of those missing, fighting for life, and their families,” Korean President Moon Jae-in said on Twitter on Sunday.

“We will work closely with the Nepali government and do our best to search and rescue (them). We will do our best to provide consular support to the families of the missing. I express my deep consolations to the families who are waiting (for their return). It is even more regrettable that they were on an education volunteer program.”

The government has sent officials to provide support to the families of the missing people. A team consisting of two officials from the Foreign Ministry and two from the education office left for Kathmandu on Saturday along with three people from the tourism agency and six members of the missing people’s families. Two more officials from the Foreign Ministry have also been dispatched.

Separately, nearly 200 trekkers in the snow-hit Annapurna region were evacuated on Saturday and brought to safety.

Earlier this morning, another volunteer group from the South Chungcheong Province Office of Education returned to Korea. The education office had sent a total of 39 teachers in three groups in January as part of its overseas volunteer program, which started in 2012. A second group of volunteers is expected to return Tuesday. The missing people were part of the third dispatch.

“The local weather was really pleasant, so we couldn’t have predicted an accident like this,” an official from the first group told reporters upon returning, adding that the first and second group had gone trekking in the same area.

“The trekking course was the same one where elementary school students (are allowed), so we didn’t realize it was dangerous. If we were aware of the bad weather, we could have contacted the education office. But due to a poor (communication) network, we couldn’t.”

By Ahn Sung-mi (sahn@heraldcorp.com)