Huge quantities of rainfall since Tuesday have severely disrupted life in the country's capital Seoul, submerging streets, flooding subway stations and forcing businesses to shut.
Rainfall in the capital on Wednesday came in at 12 inches, the biggest one-day amount since 1998 and the third highest ever, the Korea Meteorlogical Administration has said.
Landslides, flooding and accidents have caused the fatalities so far, and at least 12 more people are confirmed missing.
The Defence Ministry has now warned that mines placed on the Wumyeon Mountain in southern Seoul could have slipped down.
Soldiers with metal detectors have been drafted in to search for the mines. (more)