Five Russian navy ships pass between two Okinawa islands

Japan's Maritime Self-Defense Force has confirmed that five Russian navy ships have sailed from the Pacific Ocean to the East China Sea by passing through waters between two islands of Okinawa Prefecture.

The MSDF says the ships navigated through Okinawa's main island and Miyakojima Island in southwestern Japan on Sunday afternoon.

The ships had been spotted southeast of Cape Erimo in Japan's northernmost prefecture of Hokkaido on Wednesday.

They sailed south to waters off the eastern prefecture of Chiba, and moved near the Izu islands before passing between the Okinawa islands.

The arc of navigation means the ships sailed nearly halfway around Japan.

Japanese defense ministry sources say the ships are believed to have participated in a large-scale exercise that the Russian defense ministry said it would conduct this month in the Pacific involving at least 40 vessels.

Japanese defense officials are trying to determine the exact purpose of the navigation made by the five ships. They are also staying on the alert and continuing surveillance.