On June 7, the South Korean military detected four Chinese military aircraft and several Russian military aircraft entering South Korea's air defense identification zone without prior notice.

Russian TU-95 bomber (top) and Chinese H-6 bomber. (Source: Korea Joongang Daily)

According to Yonhap, Mr. Lee Seung-beom, Director of the International Policy Department of the South Korean Ministry of National Defense, on June 7 sent a "stern" protest note to China and Russia regarding the two countries sending fighter jets into South Korea's air defense identification zone ( ADIZ ) without prior notice.

The South Korean military said on June 7 that it detected four Chinese military aircraft and several Russian military aircraft entering the South Korean air defense identification zone without prior notice. The South Korean Air Force immediately dispatched fighter jets to the scene.

However, the Chinese and Russian planes did not violate South Korean airspace.

The development came hours after Chinese and Russian air forces conducted a joint strategic patrol earlier in the day.

Mr. Lee Seung-beom expressed regret over the incident in a note sent to military attaches at the Chinese Embassy and the Russian Embassy in Seoul.

In a press release, the South Korean Defense Ministry expressed concern as the two countries sent aircraft into sensitive areas near "our airspace."

The ministry also called on Beijing and Moscow to take appropriate measures to prevent the above actions from recurring, noting that such intrusions could cause tension in the region.

According to China's Ministry of National Defense, the joint patrol was carried out in "relevant" airspace over the Sea of ​​Japan and the East China Sea.

The patrol is part of an annual cooperation plan between the Chinese and Russian militaries, the ministry said.

This is the sixth joint strategic air patrol conducted by the two militaries.

An air defense identification zone is not territorial airspace but is demarcated to require foreign aircraft to identify themselves to prevent unexpected clashes./