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.

China and Japan clash over 'dangerous' radar incident as Chinese jets target Japanese aircraft near Okinawa, escalating military tensions between the nations.

The United States has for the first time criticised China for aiming radars at Japanese military aircraft during a training exercise last week, incidents that the Asian neighbours have given differing accounts of amid escalating tensions.

Authorities assessed the damage from Monday's 7.5-magnitude earthquake, amid warnings of aftershocks and potentially larger tremblor in the coming days.

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.