China's four-day exercise started Thursday afternoon and will end on Monday around 4 p.m., the Liaoning Maritime Safety Administration said in a notice.
The maritime safety agency demarcated a rectangular area west of of Dalian, in Liaoning province, China, as the general vicinity for where the drills would take place. Beijing's navy operates a key base for its North Sea Fleet in Dialian, according to SCMP. It's unclear how many vessels will participate in the exercise.
Japan, South Korea and US naval ships joined forces to practice detecting ballistic missile launches this week. Four guided missile destroyers, two from the US Navy and one each from the South Korean and Japanese fleets, participated in the drill, which marked the sixth trilateral naval drill since the start of 2017. Each destroyer is equipped with the US-made Aegis ballistic missile defense system, which is supposed to detect, track and neutralize ballistic missiles.
On December 6, the People's Liberation Army Air Force conducted training flights "in routes and areas it has never flown before" over the Yellow Sea dividing China and the Korean Peninsula as well as the East China Sea between China and South Korea, Japan and Taiwan.