CHINA condemned Japan’s dangerous behavior in the East China Sea after Japanese military planes entered China’s air defense zone during maritime exercises with Russia.

It demanded the country “stop all reconnaissance and interference activities, or Japan would be solely responsible for all consequences.”

China’s defense ministry said two Japanese airplanes — identified as an OP3C and a YS11EB — entered the East China Sea Air Defense Identification Zone on Saturday morning “to scout and interfere with the China-Russia naval drills” and such dangerous actions seriously violated international laws.

Chinese warplanes were scrambled to take necessary identification and preventive measures to ensure the safety of the warships and aircraft taking part in the drills, the defense ministry said.

Japan’s actions could have easily caused a misunderstanding resulting in a mid-air incident, the ministry said in a statement in response to Japanese claims that Chinese military airplanes had been “unusually close” to the jets from its self-defense forces.

Japan said Chinese SU-27 fighters came as close as 50 meters to a Japanese OP-3C surveillance plane near the Diaoyu Islands on Saturday and within 30 meters of a YS-11EB electronic intelligence aircraft.

China’s defense ministry said the joint navy exercises were part of a routine drill held by China and Russia.

“No fly” and “no sail” notices in relevant waters and airspace had been issued according to international practice, it said.

Chinese planes had the right to safeguard China’s air safety and take necessary identification and preventive measures where foreign jets enter the identification zone, it said.

“Japanese military planes intruded on the exercise’s airspace without permission and carried out dangerous actions, in a serious violation of international laws, which could have easily caused a misunderstanding and even led to a mid-air accident,” it said.

China has demanded Japan respect the legitimate rights of Chinese and Russian navies, restrain the personnel concerned and stop all reconnaissance and interference activities.