US, China Vie for Aquatic Gold at Olympics

China's Cao Yuan (R) hugs his team mate Zhang Yanquan after their last dive in the men's synchronized 10m platform final during the London 2012 Olympic Games at the Aquatics Centre July 30, 2012.

The third full day of competition at the London Olympics launched Monday, with 12 gold medals up for grabs.

Romania's Alin George Moldoveanu won the first gold of the day in the 10-meter air rifle. He beat top-ranked Niccolo Campriani from Italy.

At Wimbledon, Switzerland's Roger Federer and America's Serena Williams battled opponents in their respective matches as they sought to extend their medal races to the next round.

Swimming

Meanwhile at the Aquatics Centre, four gold medals in swimming are on the line later in the day. Swimmers will compete in the finals for the men's 200-meter freestyle and 100-meter backstroke and the women's 100-meter backstroke and 100-meter breaststroke.

Also in the pool Monday,
Also in the pool, China won its second straight gold medal in men's synchronized 10-meter diving, while U.S. swimming star Michael Phelps began the defense of his 200-meter butterfly title - an event he has won at the last two Olympic Games.

Monday also features the finals in men's gymnastics, women's 58 kilogram and men's 62 kilogram weightlifting, women's fencing and men's and women's lightweight judo. The women's basketball qualifying games include the United States against Angola.

Doping evictions

Three days into the Games, Olympic and team officials have removed three athletes from competition on suspected drug violations. The event's anti-doping chief Arne Ljungqvist told reporters that there is no way to guarantee this year's Olympics will be "completely clean." But he said officials are using a state-of-the-art doping laboratory to test blood and urine samples from every medallist.

"We do not simply do random testing to that extent as we used to do before. We do it much more on solid information that could be of importance for finding, if so, the cheats," Ljungqvist explained.

The Games last through August 12. More than 10,000 athletes from around the world are competing in 26 sports.

Photo Gallery: Olympics Day 2

Day 2 of Competition