The Ministry of National Defense lodged complaints against the Chinese military attaché and Russian defense attaché to Korea on Friday after their military aircraft entered Korea’s air defense identification zone (Kadiz) on Thursday.

Ministry official Lee Seung-beom, complained in calls to the attachés about their unnotified flyovers.

“Fighter jets from both countries flew over [security-wise] sensitive areas near Korea’s sovereign airspace after entering into Kadiz without prior notice,” Lee said in a phone call today.

Lee added that Thursday’s actions could escalate tensions within the region and called for measures to prevent recurrence.

Korea’s Joint Chiefs of Staffs (JCS) said that two Chinese military aircraft and four Russian military aircraft entered the Kadiz at 11:53 a.m. and exited 12:10 p.m. on Thursday.

The Korean Air Force immediately brought fighter jets to the scene.

The JCS viewed Thursday’s incursion as part of joint air drills between the two countries.

The authority confirmed that the dispatch of Korean fighter jets was a tactical action to respond to possible contingent situations. It also said that there was no intrusion into Korean airspace.

It is international customary practice to notify countries in advance when a military aircraft might enter or fly over their defense identification zone.

BY LEE SOO-JUNG, SARAH KIM, BAE JAE-SUNG [lee.soojung1@joongang.co.kr]