South Korea says its jets fired warning shots at a Russian surveillance plane that entered its airspace on Tuesday.
Officials said the plane twice violated the airspace over the Dokdo/Takeshima islands, which are occupied by Seoul but also claimed by Japan.
South Korea’s Ministry of Defence said it scrambled fighter jets in response and fired 360 machine-gun rounds.
Russia has denied violating the country’s airspace.
Moscow said two of its bombers carried out a planned drill over “neutral waters” and denied any warning shots were fired by South Korean jets.
This is the first incident of its kind between Russia and South Korea.
According to report, South Korea’s military said that in total three Russian and two Chinese military aircraft entered the Korea Air Defense Identification Zone (KADIZ) on Tuesday morning.
It said this group was made up of two Russian Tu-95 bombers, one Russian A-50 surveillance plane and two Chinese H-6 bombers.
Russian and Chinese bombers and reconnaissance planes have occasionally entered the zone in recent years.
Overseas aircraft must identify themselves before entering the KADIZ.
South Korea said one of the Russian planes – the A-50 – flew beyond the KADIZ and entered the country’s territorial airspace at around 09:00 local time (00:00 GMT).
South Korean F-15 and F-16 planes were deployed to intercept it.