Three more Chinese athletes have been banned for taking illegal drugs at the National games, bringing the total to 13 athletes knocked out of the competition for doping.

The official Xinhua news agency reports that rower Long Shengzhong tested positive for steroids. Long helped the southern province of Guizhou in the men's quadruple sculls event.

Track and field athlete Sun Jiawei and cyclist Pan Guangchun were disqualified for abnormal blood tests.

Abnormal or positive drug tests have forced at least 13 athletes out of the quadrennial games in Guangzhou. Chinese sports have been plagued by high-profile doping scandals in recent years and authorities have cracked down on drug use especially since Beijing was awarded the 2008 Olympics.