As a drill and potential warning, China's navy just fired dozens of missiles near North Korea

These drills, which happened Aug. 4 through

Aug. 8, took place only days after North Korea launched a missile reportedly capable of hitting most of the continental U.S. As such, the drills appear to not only be about training, but about warning other nations. If war breaks out on the Korean Peninsula, China has the capability to intervene.
Underscoring the seriousness of the situation, People's Liberation Army Navy (PLAN) commander Vice Admiral Shen Jinglong and other senior flag officers were there to observe the exercise, which took place over an area of 15,000 square miles.
Source http://www.popsci.com/china-navy-live-fire-drills-near-north-korea