The ministry of national defence denounced the Japanese military aircraft disrupting the routine patrol of Chinese administrative aircraft, Xinhua reported.
The official said China's Y-8 aircraft was patrolling the southwest airspace of the East China Sea oil platform Thursday.
The two J-10 fighters were sent to monitor the Japanese fighter jets tailing the Y-8 as well as another Japanese reconnaissance plane waS spotted in the same airspace, the official said.
The official said Japanese military aircraft have been increasingly active in closely scouting Chinese aircraft.
He said the activity zone of Japanese military aircraft has also expanded recently, and this was the root cause of security disputes between the two countries concerning territorial waters and airspace.
The Chinese military will be on high alert and will resolutely protect its air defence force, the official said.
