South Korea claimed a Russian A-50 reconnaissance plane entered its airspace twice (Picture: Russian MOD).
Russia has called for an investigation over claims one of its military planes violated South Korean airspace.
South Korean fighter jets fired 360 rounds of warning to shots to drive away a Russian military plane which twice entered its airspace, according to the country's defence ministry.
Officials said the jet was part of a joint patrol with two other Russian aircraft and Chinese bombers.
Yoon Sang-Hyun, chairman of South Korea's foreign affairs committee, said Russia's acting ambassador Maxim Volkov said Russia feels "regret" over the incident.
Mr Yoon cited Mr Volkov as saying Russia thinks an investigation is necessary and has requested related information from South Korea.
Russia said two of its bombers were on a routine flight over neutral waters and did not violate South Korea's airspace.
Russia's defence ministry also denied that South Korean jets fired warning shots, though it did say they flew close to the Russian planes in "unprofessional manoeuvres".
South Korea said it was the first time a foreign military plane had violated its airspace since the end of the 1950-53 Korean War.
Mr Volkov and Russia's deputy military attache in South Korea have been summoned, as well as their chines counterparts.
According to South Korean accounts, the reconnaissance plane and two other Russian bombers entered South Korea's air defence identification zone earlier on Tuesday together with two Chinese bombers.
Although the zone is not considered a country's territorial sky, aircraft are meant to give authorities an early warning of any possible incursions.
China's defence ministry said China and Russia carried out their first joint air patrol in north-east Asia but that it did "not target any third party".