South Korea on Friday lodged a "stern" protest with China and Russia over alleged intrusion into its air defense identification zone by at least six Chinese and Russian military aircraft.
Lee Seung-bom, director general for international policy at South Korea's Defense Ministry, expressed "regret" to Seoul-based military attaches of the two nations over the entry of their military aircraft "into the sensitive areas close to our air space without prior notice," Seoul-based Yonhap News reported.
South Korea mobilized its military jets on Thursday after the intrusion.
Seoul, however, clarified the intrusion was not into South Korea's airspace as the air defense identification zone is not the territorial airspace of any nation.
In Beijing, China's Foreign Ministry spokeswoman Mao Ning said: "Chinese military aircraft were carrying out routine and conventional flight activities in international air space. This is in compliance with international law."
South Korea's Defense Ministry asked Beijing and Moscow to "take appropriate measures to prevent a recurrence, noting that such a flight could cause regional tensions."
The air defense zone is not territorial airspace but is delineated to call on foreign plans to identify themselves to prevent accidental clashes.
