China sent fighter jets into its newly claimed -- and hotly disputed -- air defense zone above the East China Sea on Thursday, the same day that Japan's military firmly insisted its own patrols over the area wouldn't stop because of Beijing's declaration. The People's Liberation Army Air Force flew warplanes, including Su-30 and J-11 aircraft, into the "air defense identification zone" that Beijing announced last week, air force spokesman Col. Shen Jinke said. A KJ-2000 -- an airborne radar early warning system -- also took flight. The Russian-developed Su-30 is a two-seat aircraft described by its manufacturer as "a highly maneuverable fighter" capable of hitting ground and sea-surface targets. The Chinese-made J-11 is a single-seat fighter also capable of ground attacks.
@highlight
Official: China warplanes fly as "defensive measure" into newly declared zone
@highlight
The planes include Su-30 and J-11 fighter jets and a KJ-2000 airborne system
@highlight
Official: China's military has been on "high alert," will act in self-defense
@highlight
A Japan official says Japan will continue patrols/surveillance of the disputed area
"... We will continue the surveillance/patrol operation with strong determination to protect our territory against @placeholder's one-sided attempt to change the status quo by force."