Japan’s Ministry of Defense (MoD) said that on December 18, 2017, the People’s Liberation Army Air Force (PLAAF) flew two Xian H-6K long-range heavy bombers, two Sukhoi Su-30 multirole fighter jets, and one Tupolev Tu-154MD electronic intelligence aircraft through the Tsushima Strait, a waterway between the Korean Peninsula and Japan. The Japan Air Defense Force (JADF) and Republic of Korea Air Force (ROKAF) scrambled Mitsubishi F-15J all-weather air superiority fighter jets and KF-16C/D, a variant of the General Dynamics F-16 Fighting Falcon, in response respectively. Japanese and South Korean defense officials said the PLAAF did not violate Japanese or South Korean airspace.A PLAAF spokesperson noted in a statement that it was the first time that PLAAF warplanes flew through the Tsushima Strait to conduct drills in international airspace saying “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.” He added it was the first time that PLAAF warplanes flew through the Tsushima Strait to conduct drills in international airspace. 

On the same day, Shaanxi Y-8 electronic countermeasures aircraft flew through international airspace between the Japanese islands of Okinawa and Miyako in the East China Sea. Taiwan’s Ministry of Defense (MoD) said this was part of a separate Chinese military drill. Taiwan dispatched aircraft and ships in response.

On December 9, 2017, China also sent two H-6K bombers, one Tu-154 MD spy plane and one Y-8 electronic countermeasures/surveillance aircraft through the Miyako Strait. Earlier on November 18 and 19, the PLAAF flew long-range bombers and support aircraft through the strait as part of what China has called “regular” drills.