The aircraft entered the country's air defense identification zone, called the KADIZ, at around 8:03 a.m. near Ieo Island and exited at 8:27 a.m. according to the Joint Chiefs of Staff (JCS).

It re-entered the KADIZ at 9:34 a.m. near the southeastern city of Pohang, and flew between Ulleung and the easternmost islets of Dokdo, eventually leaving the air defense zone at 12:51 p.m.

The JCS said it marked the first time for a Chinese military plane to fly over the East Sea this year.

It also marked the first time for a Chinese military aircraft to fly between Ulleung and Dokdo.

The Air Force deployed fighter jets to track the aircraft and sent a warning message, the JSC said.

South Korea's defense and foreign ministries plan to lodge a protest against China for entering the KADIZ without notice later in the day.

A section of the KADIZ overlaps with the air defense zones designated by China and Japan, a source of potential tension among the regional powers.

An air defense identification zone is an area of the skies declared by a state for the early identification and location of foreign planes approaching its territory. It is not defined in any international law or treaty. (Yonhap)