Japan and China have accused each other's air forces of "dangerous" behavior over disputed waters in the East China Sea.
A Japanese Defense Ministry spokesman said a Chinese fighter jet flew close to a Japanese surveillance plane where the countries' air defense identification zones overlap. The ministry also said a second Chinese warplane flew close to a Japanese electronic intelligence aircraft in the same area.
China's Defense Ministry said Japanese planes had carried out "dangerous" actions on Saturday during China's maritime exercises with Russia.
Chinese government ships and planes have periodically entered waters near the Senkaku islands, which Beijing also claims and call the Diaoyus.