The authorities are searching for a man apparently swept away by the current in a fatal swimming accident in which another man drowned in North Chungcheong Province.

According to the police and fire authorities, two men of Thai nationality in their 30s seem to have been swept away by the current in Cheongmicheon Stream, Jucheon-ri, Gamgok-myeon, Eumseong-gun, North Chungcheong Province on Sunday at approximately 3:44 p.m.

Police and fire authorities were dispatched to the scene after receiving a report from their colleagues, and arrived to find the body of one of the men floating in the water at 4:40 p.m. that day.

The second man remains missing.

The two men had gone to enjoy the Sunday by the stream with five other people, all of foreign nationality. The group reportedly are colleagues at a factory also in Eumseong-gun.

At the time of the incident, the two Thai men had gone swimming while the other group members had been fishing, according to the police.

"The spot where the two people were swimming was around an artificial weir, and the current is relatively fast there," a police officer said. "As of now, it is presumed that the accident occurred after the two were swept away by the rapid current."

The downstream sides of weirs can be very dangerous, as, even if the water appears calm, the water coming over the weir can cause a phenomenon called hydraulic jump, which can hold swimmers underwater indefinitely.

The police plan to investigate the exact cause of the accident as soon as the search for the missing man has concluded.