TOKYO, Feb. 9 (UPI) -- A Chinese naval intelligence vessel was seen sailing near Japan's territorial waters since Thursday, Tokyo's Defense Ministry said.
The ship sailed southwest of the Boso Peninsula in Chiba Prefecture and was the same vessel that was seen in the Tsushima and Tsugaru Straits since Jan. 26, Kyodo News reported.
Japan Coast Guard said they spotted a total of three ships on Tuesday outside Japan's maritime zone off the coast of Okinawa near to the disputed Senkaku or Diaoyu Islands, also claimed by China and Taiwan.
Japan has identified Chinese vessels five times since Jan. 27, South Korean news agency Yonhap reported.
According to the coast guard's 11th regional headquarters in Naha, Okinawa, Chinese vessels equipped with heavy machine guns include vessels No. 31241, 2102 and 2305.
NHK reported the vessels were seen in February about 20 miles northwest of the Senkaku Islands, but Japanese patrol boats warned the Chinese ships and prevented their entry into Japanese territorial waters, which, according to Tokyo, extends 12 nautical miles from the claimed territory.
China and Japan have been at odds over various maritime issues.
In addition to the dispute in the East China Sea, Japan has been vocal in its opposition to Beijing's land reclamation activities in the South China Sea and has joined regional allies who have protested China's moves.
The United States and Japan plan to hold a meeting of coast guard commanders and their Australian and Philippine counterparts in order to build a unified front against Beijing's maritime projects, Kyodo News reported Tuesday.
The meeting would be the first of its kind, according to Japan press.