TOKYO, July 1 (Reuters) - Japan's defence ministry said late on Friday it had spotted two Russian Navy ships in the waters near Taiwan and Japan's Okinawa islands in the previous four days, following a similar announcement this week from Taiwan.
Taiwan's defence ministry said on Tuesday it had spotted two Russian frigates off its eastern coast and send aircraft and ships to keep watch.
Japan's government said last month that repeated Russian military activity near Japanese territory, including joint drills with Chinese forces, posed "serious concern" for Japan's national security.
The Japanese ministry said two Steregushchy-class frigates were first spotted 70 km (40 miles) southwest of Japan's westernmost island of Yonaguni, in Okinawa prefecture neat Taiwan, on Tuesday morning.
The vessels sailed back and forth through the waters between Yonaguni and Taiwan, moved eastward and were last spotted on Friday in the waters between Miyako and Okinawa islands, it said, adding Japan dispatched two vessels to monitor the Russian ships.
Persons:
Kantaro Komiya, William Mallard
Organizations:
Russian Navy, United, Russian Pacific Fleet, Thomson
Locations:
TOKYO, Taiwan, Okinawa, Japan, United States, Russia, Ukraine, Japan's, Yonaguni, Miyako, Russian, Philippine