EAST SEA — Warplanes from four different countries were involved in an unprecedented confrontation over the East Sea.

According to South Korean officials, two Chinese H-6 and two Russian TU-95 bombers conducted a joint Russian-Chinese military exercise on Tuesday morning.

CNN reports that the four planes entered South Korea's Air Defence Identification Zone or KADIZ at about 8:40 a.m., and remained for 24 minutes.

Seoul claims a Russian A-50 plane then flew beyond the KADIZ and entered airspace over the contested islands claimed by both South Korea and Japan.

The plane flew over the islands, known to the Koreans as Dokdo and the Japanese as Takeshima, at 9:09 and then again at 9:33 a.m.

In response, South Korea deployed F-15F and KF-16 fighter jets, which fired 10 flares and 80 warning shots the first time then 10 flares and 280 more rounds during the second.

Russia's Defense Ministry initially denied the reports and accused the Korean pilots of unprofessional maneuvers, but later confirmed that their jets had taken part in a joint patrol with China.

The BBC reports that Japan later confirmed that its military also sent fighter jets in response to the "Russian incursion."

It has since lodged a strong protest against both the Russian and South Korean over what it regards as a violation of its airspace.

CNN reports that South Korea has since dismissed Japan's protest, but have themselves sent a strong message of complaint to the Russians over the incident. Moscow has yet to respond to either country.