Russian military aircraft entered South Korea's air defense identification zone (KADIZ) without notice Tuesday, prompting the Air Force to scramble fighters to the scene, Seoul's Joint Chiefs of Staff (JCS) said.

The JCS did not provide details, like the number of Russian planes and their types.

The entry into KADIZ came amid tensions between Seoul and Moscow over the latter's invasion of Ukraine and the former's participation in international moves against the armed conflict.

"Regarding the Russian military aircraft's entry into KADIZ, our military took tactical steps in preparation against possible accidents," the JCS said in a statement.

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. (Yonhap)