An explosion killed six workers and injured nine others at an illegal fireworks plant in southwest China's Guizhou Province Saturday, Xinhua reported. The blast took place at 4:20 p.m. in Pingqiao Village, Buyei-Miao Autonomous Prefecture of Qianxinan, a spokesman for the provincial work safety bureau said Sunday. Five workers died at the site and 10 injured people were rushed to hospital, one of whom died despite doctors' effort, according to the local work safety authority. Most of the dead and the injured were villagers. The seriously injured have been transferred to a hospital in the prefecture seat. An investigation is underway.