China sent several warplanes on a long-range drill to the Sea of Japan on Monday and also conducted drills around rival Taiwan, a move that prompted South Korea to scramble fighter jets and could raise concerns about Beijing's growing military presence in the region.
Chinese air force spokesman Shen Jinke said the air force dispatched bombers, fighters, and reconnaissance planes through the Tsushima Strait to the Sea of Japan to "test its ocean combat ability."
"This is a regular annual training arrangement of China's air force that accords with the relevant international laws and practices and it isn't aimed at any particular state, region, and target," Mr. Shen said in a statement.
This was the first time the Chinese air force has flown through the strait that lies between South Korea and Japan, Shen said.
Seoul's Joint Chiefs of Staff said five Chinese warplanes – two bombers, two fighter jets, and one reconnaissance plane – entered South Korea's air defense identification zone off a southern South Korean island almost at the same time on Monday.
They then flew to the Japanese air defense zone above the waters between the Korean Peninsula and Japan, a JCS official said on condition of anonymity, citing department rules.
The official said the Chinese planes entered the South Korean air defense zone again before returning to China.
South Korea used a military hotline to warn China of its planes' entrance to the zone and China replied that it's part of routine training, the official said.
Self-ruled Taiwan's military says China's air force held a separate drill Monday morning through the Bashi Channel separating Taiwan from the Philippines and then through the Miyako Strait, which lies north of Taiwan and to the south of Japan.
The Taiwanese defense ministry said Japan dispatched F-15 fighter jets to intercept the Chinese planes. Japan had no immediate comment on Monday's drill.
It was the second time in two days that China conducted drills around Taiwan, a self-governed island China claims as its own territory to be brought under its control by force if necessary.
China has also taken a tougher stance toward Taiwan since last year's election of independence-leaning President Tsai Ing-wen, who has refused to endorse Beijing's contention that Taiwan is part of the Chinese nation. Beijing has exerted pressure mainly through diplomatic and economic measures, although Chinese commentators frequently speculate on the potential need for military steps to bring additional pressure on Ms. Tsai.
Japan's Defense Ministry said Monday that three Chinese military aircraft – one Y-8 surveillance aircraft and two Y-8 electronic warfare aircraft — caused Japanese fighter jets to scramble Sunday.
The ministry said they violated Japan's air defense identification zone while flying above the waters of the East China Sea and the Pacific between the Japanese southern islands of Okinawa and Miyako.
The flight continued for a few hours from mid-morning to early afternoon, a ministry official said on condition of anonymity, citing department rules.
The official declined to give any other details, including the number of Japanese fighters that were mobilized, or what might be behind the Chinese aircraft flights.
This story was reported by The Associated Press.