South Korean news agency Yonhap reported that a fire broke out on board a Russian fishing vessel off the coast of South Korea.
The agency quoted the South Korean Coast Guard as saying that the fire broke out at 0:43 local time on board a ship that was carrying 100 tons of seafood bound for Russia.
The accident occurred near the port of Ulsan in the southeast of the Korean Peninsula, and the Coast Guard sent a rescue ship to the area after receiving a distress call.
There were 25 people on board the Russian ship, all of them Russian citizens, and the South Korean authorities rescued 21 people, two of whom were slightly injured.
The search is still on for 4 crew members of the Russian ship.