When you conduct military exercise in South China Sea, be prepared for China to conduct military exercise near your sea too.

http://www.asianage.com/india/all-india/190517/india-singapore-navies-conduct-joint-exercise-in-s-china-sea.html

India and Singapore conducted military exercise in the South China Sea in May 2017.  Therefore, it is not surprising to see China conducting exercises in Indian ocean too.

http://en.people.cn/n3/2017/0718/c90000-9243240.html