South Korean, US and Japanese fighter jets take part in a trilateral air exercise in April 2024 near overlapping air defense identification zones between South Korea and Japan off Jeju Island. (Ministry of Defense) South Korea scrambled fighter jets Saturday after more than 10 Chinese and Russian military aircraft entered its air defense identification zone over the East Sea and waters off the country’s south, Seoul’s military said.The aircraft entered and left the Korea Air Defense Identification Zone in sequence earlier in the day, but did not violate South Korean airspace, according to the Joint Chiefs of Staff.“Our military identified the Chinese and Russian aircraft before they entered the KADIZ and deployed Air Force fighter jets to take tactical measures in preparation for possible contingencies,” the JCS said.An air defense identification zone is not territorial airspace, but a buffer zone designated to identify foreign aircraft before they approach a country’s airspace and prevent accidental clashes.Foreign military aircraft are generally expected to notify the relevant country before entering such a zone, although an ADIZ has no status under international law.A JCS official said the entry appeared to have taken place during a joint air exercise by China and Russia.Chinese and Russian military aircraft also entered and left South Korea’s air defense zone in December 2025 and November 2024.