Efforts to search for two Korean climbers that went missing last week in the Himalayas have run into difficulties.

An official from the Foreign Ministry in Seoul said Tuesday that helicopters and a Sherpa guide are assisting efforts to find Yun Chi-won and Park Haeng-su, who went missing while attempting to come down from Manaslu Mountain.

The two men were part of an expedition made up of six employees of the Korea Expressway Corporation. The remaining four members of the expedition were rescued and are being treated at a local hospital.

The ministry official said search efforts are facing difficulties due to bad weather conditions, including thick fog.

Members of the alpine society of the Korea Expressway Corporation will arrive in Nepal on Tuesday to join search operations.

Standing at eight-thousand-163 meters, Manaslu is the world's eighth highest peak and is located in the middle of the Himalayas in Nepal.