Toxic waste sparks violent protest at China factoryMon Aug 22, 3:05 AM ET BEIJING (Reuters) - Chinese protesters set fire to factory buildings and police cars in a clash sparked by toxic waste, police and residents said on Monday, the latest illustration of a growing wave of public dissent. Saturday's violence at the Tian Neng Battery Co. was also the third protest in the eastern province of Zhejiang in recent months caused by pollution, highlighting the environmental price of China's rise to become the world's seventh-largest economy. "It's very serious. There was a clash between protesters and the police. Some...