A total of six workers were killed and another one injured in two fireworks plant blasts Friday in China, Xinhua quoted local government sources as saying. One blast occurred in an illegal workshop at around 5:30 p.m. in Yishui County, east China's Shandong Province. It killed a couple on the spot and injured their son. The local government is investigating. The second explosion was at around 7:50 a.m. in Qinzhou City, south China's Guangxi Zhuang Autonomous Region, leaving four workers dead. Initial investigation showed that a mistake by workers caused the blast, and the plant owner has been held by police. Authorities in Qinzhou have ordered production halts at all fireworks plants for work safety checks.