South Korea scrambles jets as China and Russia fly warplanes into its air defense zone

Seoul — South Korea's military said Thursday it scrambled fighter jets as two Chinese and four Russian military planes entered its air defense zone, an area wider than the country's airspace. The Chinese and Russian planes entered and exited the Korea Air Defense Identification Zone (KADIZ) in the East Sea, also known as the Sea of Japan, for just less than 20 minutes around midday local time, Seoul's Joint Chiefs of Staff said.

But "there was no invasion of airspace," the joint chiefs added, and the South Korean military identified the planes "before they entered KADIZ, and deployed air force fighter jets to take tactical measures in preparation for contingencies."

An air defense identification zone is a broader area than a country's airspace in which it tries to control aircraft for security reasons, but the concept is not defined in any international treaty.