The defence ministry says four bombers, supported by fighter jets, patrolled a pre-planned route over the Sea of Japan and the East China Sea. South Korea says its jets fired flares and machine-gun warning shots when Russian planes intruded.
The alleged incursion happened over the disputed Dokdo/Takeshima islands, which are occupied by South Korea but also claimed by Japan. Russian and Chinese bombers and reconnaissance planes have occasionally entered the zone in recent years, but this is the first incident of its kind between Russia and South Korea.
The defence ministry said two of its Tu-95MS strategic missile-carriers had joined two Chinese Hong-6K strategic bombers on the pre-planned route over “neutral waters”.
They were supported by fighters and A-50 and Kongjing-2000 airborne early warning and control aircraft.
At one point the patrol became a “single airborne formation consisting of a line of pairs of planes flying within 3-4km [around two miles] of each other”, Lt-Gen Sergei Kobylash said in a televised statement.