Annapurna is an avalanche-prone and technically difficult mountain range with a higher death rate than Everest, the world's highest peak
Four South Koreans and three Nepalis are missing and about 200 people have been rescued after an avalanche hit trekkers on the Annapurna region in the Himalayas, officials said Saturday.
South Korea was to send an emergency team to Nepal to help in a desperate search operation.
The incident occurred at an altitude of about 3,230 metres (10,600 feet) close to Annapurna base camp following heavy snowfall on Friday.
Six of the missing are from one trekking expedition while one Nepali porter is from a different group.
"A search operation is underway for the seven out of contact," Mira Acharya of Nepal's tourism department told AFP.
About 200 people have been rescued from the avalanche-hit zone as well as other trekking routes after the weather eased to let helicopters fly in.
The four were part of an 11-member team from South Korea. Others from the team are safe.
Ang Dorjee Sherpa of the Korean Alpine Federation said it had been snowing in the area since the last two days, making their trek risky.
"The weather and snow got worse and, feeling it was becoming dangerous and difficult, they decided to turn. As they were heading back they were hit by an avalanche," Sherpa said.
Annapurna is an avalanche-prone and technically difficult mountain with a higher death rate than Everest, the world's highest peak.
Kim Sung-hwa, a South Korean trekker in Kathmandu after a trek in the Langtang region in eastern Nepal said he had to cut his trip short after abnormally heavy snow.
"Winter is a dry season (in Nepal) and you don't (normally) see a lot of snow. But due to abnormal weather conditions... even here, when we went to Langtang, there was a heavy snow and rain," Kim said.
"I heard the news this morning and as a trekker and a fellow (South Korean) citizen who like and love Nepal, I feel heart-stricken."
Education officials in South Korea said the four South Koreans were part of a team of volunteer teachers working with children in Nepal.
South Korea's foreign ministry said an emergency team would be sent to Nepal and that the families of those missing had been informed. The volunteers were from Chungcheong province.
Thousands of trekkers visit the Annapurna region every year for its stunning views of the Himalayas.
In 2014, a snowstorm killed about 40 people on the popular circuit, in one of the biggest trekking tragedies to hit Nepal.