Japanese fighter pilots have engaged in provocative behavior and conducted irresponsible and dangerous maneuvers - once deliberately flying perilously close to a Chinese aircraft, Beijing said on Thursday as the details of intrusions on a joint China-Russia military drill last weekend continued to unfold.

"Japanese military aircraft have conducted, on at least 10 occasions, deliberate close encounters against regular Chinese flights" since China established its Air Defense Identification Zone in the East China Sea in November, Geng Yansheng, a Ministry of National Defense spokesman, told reporters in Beijing.

The incident on Saturday morning, when two Japanese reconnaissance aircraft entered the East China Sea ADIZ during a China-Russia naval drill, resulted in an exchange of heated remarks.