KATHMANDU/SEOUL -- South Korea's top envoy to Nepal has asked Nepalese authorities to continue efforts to find four South Koreans missing after an avalanche in the Himalayas, amid slow progress in search operations owing to bad weather.

Monday's air and ground searches for the four people missing at the Annapurna trekking site were called off for the day as unfavorable weather conditions blocked officials from approaching the scene where the missing people are believed to be trapped.

The school teachers from South Korea's central South Chungcheong Province went missing after a snowslide struck the popular trekking route in northwestern Nepal on Friday. Three Nepalese guides also remain unaccounted for.

"Although the situation is difficult due to the risk of more snowslides, I ask the Nepalese government to make continued efforts so that the four missing people can be found," Ambassador to Nepal Park Young-sik said in a press conference held in Pokhara, a city near Mount Annapurna, later on Monday.

Also speaking to local and foreign media was Dan Bahadur Karki, police chief of Nepal's Kaski district.

Park expressed concerns that a prolonged search could tire the rescue team out, as well as some 20 residents from the area who have also been helping out in the search.

"That is what worries the families of the missing people as well," he added.

Karki, who's in charge of the rescue work, said that the rescue team has marked two spots at the accident site that reacted to signals sent from its electronic detectors.

The reactions could have come from electronic devices that belong to the missing people, suggesting that's where the four South Koreans are likely located, the police chief said.

The police chief said the rescue team has secured a red plastic bag and an unidentified yellow item that are believed to be belongings of the missing people.

He also did not rule out the possibility of survival but said that future operations will depend on weather conditions.

Nepalese officials have mobilized military personnel and helicopters for the search operations. But heavy snowfall and additional avalanches that occurred following the accident have been hampering the rescue efforts.

An official from Nepal's tourism ministry said earlier that the search could take at least a few weeks as the weather needs to clear for the operation to speed up the process.

The four missing -- two women in their 30s and 50s and two men in their 50s -- were among a nine-member team on a trekking course in the Deurali part of the Annapurna Base Camp when the avalanche engulfed them. The five others were rescued by a chopper from a nearby lodge.

The teachers were part of a 39-member volunteer team dispatched to Nepal by the education office of South Chungcheong Province. (Yonhap)