TOKYO—Russian and Chinese bombers flew near Japan and South Korea in a joint patrol Tuesday that Tokyo described as a show of force, adding further strain to the worst diplomatic crisis in years between Tokyo and Beijing.

Russian and Chinese bombers conducted a joint patrol Tuesday, flying over the East China Sea and Western Pacific, prompting Seoul and Tokyo to scramble fighter aircraft to monitor the flights. At approximately 10:00 a.

Japan has scrambled jets to monitor Russian and Chinese air forces conducting joint patrols around the country, the Japanese defense ministry said late Tuesday, amid rising tensions between Tokyo and Beijing.

Two Russian nuclear-capable bombers flew from the Sea of Japan toward the East China Sea to join two Chinese bombers for a “long-range joint flight” above the western Pacific.

No end in sight to spat between Japan and China over Taiwan, as neither Tokyo nor Beijing shows signs of backing down.

The 15-year effort by Japan is a model for countries now scrambling to reduce their dependence on Beijing’s critical metals.

Denryu Lin, who runs about 80 vacation rentals in central Osaka, is watching his business evaporate since late November as tensions between Tokyo and Beijing escalate.

Japan is threatening China militarily which is "completely unacceptable", Chinese Foreign Minister Wang Yi told his German counterpart, after Japan said that Chinese fighter jets had aimed their radar at Japanese military aircraft.