Four Chinese vessels were just outside territorial waters around the Senkaku Islands in the East China Sea on Tuesday morning. The marine surveillance ships were navigating in the contiguous zone near Kubajima, one of the islands. This was after they entered the waters off Uotsuri island on Monday and left during the night, according to Japan's (NHK WORLD) website. Japan's Coast Guard is using radio communication to warn the ships away from Japan's territorial waters and is continuing to monitor them. Some of the Chinese vessels temporarily entered Japan's territorial waters on October 2nd and 3rd. The Senkaku Islands dispute concerns a territorial dispute over a group of uninhabited islands known as the Senkaku Islands in Japan and as the Diaoyu (in China) or Tiaoyutai Islands (in Taiwan). Aside from a 1945 to 1972 period of administration by the United States, the archipelago has been controlled by Japan since 1895. The People's Republic of China (PRC) disputed the proposed US handover of authority to Japan in 1971.