BEIJING -- Japanese military planes have intruded on the airspace of China-Russia naval exercises and carried out dangerous actions, seriously violating international laws, China's Ministry of National Defense said Sunday.

Two Japanese airplanes, OP3C and YS11EB, intruded into the East China Sea Air Defense Identification Zone on Saturday morning to scout and interfere with the China-Russia naval drills.

Chinese warplanes took off instantly to take necessary identification and preventive measures to ensure the safety of the warships and aircraft in the drills, said the ministry.

Japan's actions could have easily caused a misunderstanding and even led to a mid-air incident, a ministry statement said, in response to Japanese media reports that Chinese military airplanes had been "unusually close" to the jets of Japan's Self-Defense Forces.

The exercises in the designated waters and airspace was a routine drill held by China and Russia. "No fly" and "no sail" notices in relevant waters and airspace had been issued ahead of the exercises according to international practice, the ministry said.

Chinese warplanes have the right to safeguard China's air safety and take necessary identification and preventive measures in case foreign jets enter the identification zone, it said.

China has demanded Japan to respect the legitimate rights of Chinese and Russian navies, restrain the personnel concerned and stop all reconnaissance and interference activities. "Otherwise, Japan shall be responsible for all the consequences," the statement said.