"Three Chinese patrol ships temporarily patroled Chinese territorial waters near the Diaoyu (Senkaku) Islands in the East China Sea on Wednesday," reported Japan's media outlet NHK, citing the State Oceanic Administration of China statement.
Chinese ships remained in the area for several hours, before moving to the contiguous zone just outside of Japanese waters. No other details of Chinese ships' actions have been available.
According to the Japanese media outlet NHK, a special headquarters has been established at the office of Prime Minister of Japan Shinzo Abe to deal with the matter.
It is the 4th time this year that Chinese government vessels have entered Japanese waters off the Senkaku islands, with the previous incursion taking place on February 13th, local media reported.
The tensions over the Senkaku Islands have been escalaiting in recent months, with the countries to the conflict accusing each other of provocations.
Japan and China have disputed ownership over the uninhabited Senkaku Islands, called in Chinese the Diaoyu islands, since the 1970s. China says that the contiguous islands have been part of its territory since antiquity. Japan claims the islands have been under its control since 1895. Japan is currently in control of the islands.