Japan detects unidentified sub outside Okinawa waters

An unidentified submarine has been detected late on Sunday near Japan’s maritime border south of Okinawa’s Kumejima Island, Japanese Defense Ministry says.

A group of Japan’s war planes and navy forces tracked a submarine cruising eastward just outside Japanese waters.
It reportedly left the border area by Monday morning and proceeded in the southeastern direction, the source said.
According to Japan’s Defense Ministry, another unknown submarine turned up west of Amami-oshima Island in Kagoshima Prefecture on May 2. It left soon afterwards.