The explosion toppled the three-story building in east China's Jiangsu Province in an industrial hub in the Yangtze River Delta, China's official Xinhua news agency reported.
Whether the building was residential or industrial was not reported.
Nine people were hospitalized, at least three of whom were in critical condition, Xinhua said. Several people were still buried under the wreckage of the building.
Jessica Simpson shares three-way kiss with friends in photo
Susan Sarandon 'very excited' about daughter's pregnancy