Three North Korean fishermen are missing after their boat and a South Korean cargo ship collided in the Yellow Sea, coast guard officials said on Tuesday.
The accident occurred late on Monday on the northern side of the inter-Korean maritime border.
One fisherman was rescued before his boat sank by the South Korean ship whose 10 crew were all safe, according to the Incheon Coast Guard.
The man rescued was to be returned to North Korea, Incheon Coast Guard spokesman Lee Pyung-Hyun said.
Some 30 North Korean fishing boats were seen searching for the missing, the spokesman said.