Seven sailors are missing after a fishing boat caught fire in waters near Hawangdeung Island in Buan County, North Jeolla Province.

According to the Buan Coast Guard Station on Thursday, the 34-ton vessel caught fire at around 8:39 a.m., in waters four kilometers east from Hawangdeung Island.

Out of 12 sailors who jumped into the water without a life jacket, five - two South Koreans and three Indonesians - were rescued.

All of those rescued are being treated for hypothermia.

Seven others - a South Korean captain, another South Korean and five Indonesians - are still missing as of 5 p.m.

The Coast Guard said the probability of their survival was falling with passing time with the water temperature ranging at around five degrees Celsius.

Authorities plan to continue the search into the night using guardships, divers and drones.

They will also analyze the vessel in question to determine the exact cause of the fire.