Tokyo sent a note of protest to Beijing after a Chinese frigate entered the disputed territory in the East China sea, said the press-Secretary of the Ministry of defense of Japan.
Japanese Navy destroyer discovered a Chinese ship when it entered the contiguous zone in the tension zone of 24 nautical miles from the edge of the territorial waters around the Senkaku Islands, also known as the Diaoyu island 12:50 a.m. local time on Thursday, Akitomo Mori told CNN. It was the first case where a Chinese frigate entered the contiguous zone, he added.
"We are deeply concerned that Chinese naval vessels entered the waters adjacent to our Senkaku Islands for the first time," the chief Cabinet Secretary of Japan yoshihide Suga told reporters on Thursday.
According to Japanese officials, the Minister of foreign Affairs Deputy Minister Akitaka Saeki summoned the Chinese Ambassador, Chen Agha to file a protest "with grave concern" and asked that a Chinese warship has left the area immediately.
Both China and Japan claim ownership of Senkaku, tensions flared several times in recent years.
In late 2013, China announced the identification of air defense zone in the East China sea, including Senkakus, despite objections from Tokyo and Washington.
sections: Politics, World News, Accidents