BEIJING, May 29 -- China on Thursday criticized Japan's intrusion into the East China Sea Air Defense Identification Zone(ADIZ), calling the move another example of Japan's repeated provocation.

"Japanese Self-Defense Forces jets' intrusion into the East China Sea ADIZ poses a threat to our air defense and security," Defense Ministry spokesman Geng Yansheng said at a monthly press briefing.

Geng's comments came in response to Japanese Defense Minister Itsunori Onodera's remarks that Japan conducted regular warning and surveillance activities according to international law.

Two Japanese airplanes, OP3C and YS11EB, intruded into the East China Sea ADIZ on Saturday morning to scout and interfere with China-Russia naval drills, according to a statement issued by the Chinese Defense Ministry on Saturday.

"Japan's move, like its decision to purchase the Diaoyu Islands in 2012, is very dangerous and provocative," Sun Jianguo, deputy chief of General Staff of the People's Liberation Army, said on the sidelines of an international security seminar on Tuesday. In recent years, Japan has frequently made reconnaissance and surveillance forays by sea and air into Chinese territory.

Geng also criticized Japan for upping the tension. "What is behind Japan's moves? Japan should give the international community a clear explanation."