The Japanese cargo ship Byakko collided with a small tanker Ulsan Pioneer, registered in the Marshall Islands, reports NHK.
It happened off the coast of Shikoku Island. As a result of the collision, the Japanese ship capsized. Of the 12 crew members, nine were rescued, and three more are still unknown.
Onboard the tanker was 13 sailors-citizens of South Korea and Myanmar. None of them were injured.