Four Chinese maritime surveillance vessels entered Japanese territorial waters Thursday morning around the disputed Senkaku Islands in the East China Sea, the Japan News Agency (Kyodo) reported. Chinese ships sailed in the area near the Japan-administered chain of islets claimed by China for the third day in a row and for the 17th time after the purchase of three of the islets by the Japanese government in September. After a coast guard vessel ordered them out via radio, one of the Chinese ships responded in Chinese, saying the islets have been China\'s territory \"since ancient times,\" according to the 11th Regional Coast Guard Headquarters in Naha, Okinawa Prefecture.