Russia and China air drills 'serious concern' for Japan security - government

China and Russia's joint air drills around Japan are a "serious concern" for national security, Japan's top government spokesperson said on Wednesday.

China and Russia conducted a joint air patrol over the Sea of Japan and the East China Sea on Tuesday, prompting neighbouring South Korea and Japan to scramble fighter jets.

Japan also spotted Chinese and Russian bombers flying together on Wednesday, Chief Cabinet Secretary Hirokazu Matsuno said.