The two warplanes left the area around 7 a.m. but returned about five hours later with six Russian warplanes. Around 12:20 p.m. the eight aircraft flew into the air defense zone via the Sea of Japan, departing the area eighteen minutes later. The Russian planes included Tu-95 bombers and Su-35 fighter jets.
South Korea sent out an unknown number of airplanes, including F-15K jets.
“Our military dispatched air force fighter jets ahead of the Chinese and Russian aircraft’s entry of the Kadiz to implement tactical measures in preparation for a potential contingency,” the JCS said in a statement.
“Around the same time, what appears to be two Russian aircraft flew south over the Sea of Japan and then turned around,” it said.
Seoul also noted that the war aircraft departed the area and did not breach South Korea’s airspace.
Air defense identification zones are regions separate from a country’s airspace, and nations insist that foreign aircraft take additional identification measures when operating in them. The zones, however, are not under international rules and the idea is not clarified in international treaties.
Yonhap, a news outlet out of South Korea, reported that Russia and China seemed to have “engaged in a combined air exercise.”
Russia said its planes and the Chinese aircraft ”carried out air patrols over the waters of the Japanese and East China Seas.” It claimed that the planes “acted strictly in accordance with the provisions of international law” without breaching foreign airspace.
Russia and China have previously deployed war aircraft into the KADIZ.
In the past, China and Russia have claimed their war aircraft were engaging in regular joint exercises. Russia does not acknowledge South Korea’s air defense identification zone, while China claims the area is not territorial and all nations should be able to fly there.