Four people are missing after a fishing boat capsized in waters off the country's southernmost island of Mara on Tuesday.

The Coast Guard received a report at around 3 a.m. that the 29-ton vessel turned over in waters six-point-eight kilometers southwest of Mara Island, south of Jeju Island.  

Coast Guard officials reportedly arrived at the scene at around 5 a.m. and found the boat capsized. Four people were believed to have been on board the vessel.

The Coast Guard has mobilized a patrol boat, special forces unit and a rescue team in the search for the missing people, as well as asking for support from the Navy and vessels in the region.