Four ships belonging to the Chinese government entered territorial waters near the disputed Senkaku islands in the East China Sea on Tuesday afternoon, according to the Japanese Coast Guard.
The coast guard called on the ships by radio to leave the area, Kyodo reported. Foreign Minister Koichiro Gemba told a press conference that Tokyo has filed a complaint with the Chinese government over the incident.
“Patrol ships from our agency have been telling them to sail outside of our territorial waters. There has not been any response” from the Chinese ships, the Japan Coast Guard said.
The Senkaku Islands, which are called Diaoyu in China and Tiaoyutai in Taiwan, are a group of uninhabited islets disputed by the three countries.
China has escalated its maritime activities around the disputed islet group since the Japanese government nationalized the islet group in September.