South China Sea drills underscore China's sovereignty claims

China has launched three days of naval drills near its South China Sea island province of Hainan, underscoring its growing capabilities in defending its maritime interests.

Those exercises follow recent ones in the disputed sea featuring China's sole operating aircraft carrier that come amid deployments and drills by the rival U.S. Navy.

China's Maritime Safety Administration says the exercises began on Wednesday and would last through the end of Friday.

China is building new vessels at a rapid pace to equip its navy, coast guard and maritime law enforcement agencies, including its first entirely domestically-built aircraft carrier.

It claims virtually the entire resource-rich South China Sea, through which an estimated $5 trillion in global trade passes annually, and has constructed installations on artificial islands to enlarge its military footprint.