The Japanese Maritime Self-Defense Force has confirmed that a foreign submarine navigated an area just outside Japan's territorial waters without surfacing this week. Defense officials say they believe the submarine belongs to the Chinese Navy.

Defense Ministry officials say MSDF destroyers and patrol planes first spotted the submarine on Thursday afternoon in the contiguous zone northeast of Amami-Oshima Island in Japan's southwestern prefecture of Kagoshima. They say it was moving west and that the MSDF kept it under observation.