China conducted military “combat patrols” Sunday in the disputed South China Sea, its army said, the same day as joint drills by the Philippines, the United States, Japan and Australia.

The announcement comes one day after defence chiefs from four countries including the Philippines — which has been engaged in several contentious maritime disputes with Beijing recently — said they would conduct joint drills Sunday in the area.

Beijing’s People’s Liberation Army (PLA) Southern Theater Command said it was organsing “joint naval and air combat patrols in the South China Sea”.

“All military activities that mess up the situation in the South China Sea and create hotspots are under control,” it said in a statement, in an apparent swipe at the other drills being held in the waters.