China and Russia kicked off eight days of naval drills Monday in the South China Sea off southern Guangdong province — a move likely to further stir tensions in the disputed waters.

The joint exercises come after a July 12 ruling by the Permanent Court of Arbitration in The Hague that decisively rejected Beijing's expansive claims to much of the South China Sea. China has built artificial islands in the contested Spratly chain, including several with military-grade airfields and high-tech radar systems, in its bid to consolidate its control of the area. Beijing blasted the ruling, calling it "waste paper," and has vowed to ignore it.

The exercises, called Joint Sea-2016, feature navy surface ships, submarines, fixed-wing aircraft, ship-borne helicopters, marine corps and amphibious armored equipment from both navies, the official Xinhua News Agency quoted spokesperson Liang Yang as saying Sunday.