The Japan Coast Guard has begun interviewing the captain and crew of a Fisheries Agency patrol ship about a collision with a North Korean fishing boat the day before.
The patrol vessel entered Niigata port on the Sea of Japan coast on Tuesday morning. The ship's bow had some visible scars. About 20 Coast Guard officials have boarded the ship for the investigation.
The collision on Monday morning took place in Japan's exclusive economic zone, about 350 kilometers off the Noto peninsula in the Sea of Japan.
The patrol ship's crew rescued all of the roughly 60 North Koreans who were thrown into the sea after their boat sank. All those rescued then boarded another North Korean ship that was sailing in the area.
The Fisheries Agency says the patrollers sprayed water at the North Korean boat and told it to leave as it was inside Japan's EEZ. It says the two vessels collided because the North Korean side made a sudden turn.