Russia's Defence Ministry said on Tuesday two Russian strategic bombers - capable of carrying nuclear warheads - carried out routine patrol flights over the Sea of Okhotsk and the Bering Sea, off Russia's Far East, TASS news agency reported.
Japan's Defence Ministry later said in a statement that it had scrambled a jet fighter in response to Russian information-gathering aircraft over the Sea of Japan.
Japan's Chief Cabinet Secretary Hirokazu Matsuno said on Monday that Tokyo had lodged a protest with Russia over its military exercises around disputed islands near Japan's Hokkaido.
The incident took place on the final day of the Group of Seven foreign ministers meeting in Japan, during which the group agreed Russia must withdraw all troops in Ukraine unconditionally.
Japan's Defence Ministry later said in a statement that eight Russian vessels - two destroyers and six patrol boats - were observed moving northeast from west of Rebun island, near Japan's Hokkaido, into the Soya Strait, from Monday to Tuesday.
(Reporting by Reuters; Editing by Christina Fincher and Jon Boyle)
