China's air force said on Friday it had flown bombers and other jets through a strait between Japanese islands on their way to drills in the Western Pacific, and had carried out a patrol in China's air identification zone in the East China Sea.
"This year the air force has four times carried out drills in the Western Pacific, raising the air force's ability to fight over long distances far out at sea," it said in a statement on its official microblog.
China's ties with Japan have been strained by a longstanding territorial dispute over a string of islets in the East China Sea, known in China as the Diaoyu and in Japan as the Senkaku.
The two countries have also clashed over what China sees as Japan's refusal to take responsibility for its wartime past.
Aircraft of the People's Liberation Army did the exercises after flying over the Miyako Strait, a body of water between Japan's islands of Miyako and Okinawa, the air force statement said.
It showed pictures of H-6 bombers participating in the exercise, and said there was also a patrol with fighters and early warning aircraft in the East China Sea identification zone.
The drills were normal exercises and China will continue to carry them out in accordance with international practice, the ministry said.
China's navy has often used the Miyako Strait, a key strategic route for the military, as a pathway from eastern China to the Pacific Ocean.
China drew condemnation from Japan and the United States in 2013 when it imposed an Air Defense Identification Zone (ADIZ), in which aircraft are supposed to identify themselves to Chinese authorities.
The air force said that since the zone was set up it had been carrying out regular patrols there.