The North Korean vessel made an unauthorized entry into Japan’s exclusive economic zone, Fisheries Agency official Satoshi Kuwahara told reporters. He said the two ships collided as the Japanese patrol boat was warning the North Korean vessel to leave.
Japanese authorities have been stepping up patrols to detect North Korean ships that sail into the country’s waters for illegal fishing.
The Fisheries Agency patrol boats send warnings to such boats through water cannons or electronic signs, according to Kuwahara.
In June, Japan pushed more than 300 North Korean boats out of its fishing grounds in the same area where the collision happened on Monday.
Last month, Tokyo lodged a protest with Pyongyang after a Japanese patrol boat was threatened by what Japan said was an armed North Korean boat intruding in Japanese waters.
Pyongyang disputed Japan’s claim, saying the incident occurred in North Korea’s exclusive economic zone, not Japan’s.
Monday’s incident came five days after North Korea fired a ballistic missile that landed in the Sea of Japan, also known as the East Sea. Japan condemned the launch, saying the missile fell inside its territorial waters.
Kashiwagi reported from Tokyo.