Four Chinese and four Russian military planes entered South Korea's air defense identification zone (KADIZ) without notice Tuesday, Seoul's military said, prompting the South Korean Air Force to send its fighter jets to the scene, Yonhap agency reports.
The Joint Chiefs of Staff (JCS) said that between 11:52 a.m. and 1:49 p.m., the Chinese and Russian aircraft entered the southern and eastern parts of the KADIZ, respectively, and exited it. They did not violate South Korea's air space, it added.
The air defense zone is not territorial airspace but is delineated to call on foreign planes to identify themselves so as to prevent accidental clashes.
China and Russia have previously said their warplanes were conducting regular joint exercises.