China's air force on Thursday conducted a drill in the western Pacific Ocean after passing through a strait near Japan, the country's defense ministry said, as its military adopts a more assertive posture in the region.
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 ministry said in a statement on its website.
The day-long exercises aimed to improve the air force's combat capability far out at sea, the ministry said.
"The annual exercises are planned according to a routine schedule, and in line with relevant international laws and practices, not directed at any specific country," air force spokesman Shen Jinke said in the statement.
In Tokyo, Japan's defense ministry said it scrambled fighter jets against two Chinese H-6 bombers that flew over those waters, but there was no entry into Japan's airspace.
Japan scrambles jets more than 900 times a year.
China's air force has increasingly conducted drills far from its coast, state media have said.
Its navy has often used the Miyako Strait, a key strategic route for the military, as a pathway from eastern China to the Pacific Ocean.