The Japanese government created a crisis response headquarters on Monday after a Chinese patrol ship entered Japanese territorial waters next to the disputed islands in the East China Sea, NHK broadcaster reported.
Four Chinese corvettes approached the territorial waters of Japan, while one of them crossed into the Japanese area near the disputed Senkaku Islands, according to the NHK broadcaster.
The crisis response headquarters will collect information about the incident and monitor the situation, the news outlet added.
Tokyo and Beijing have long been involved in a territorial dispute over the disputed Senkaku Islands, referred to by China as the Diaoyu Islands, which are located next to important shipping routes, and potentially large oil and gas fields.