Seventeen people were killed and 20 injured on Wednesday morning in a series of massive explosions at a machinery factory in Foshan in Guangdong province, Xinhua reported. The blast happened at about 9.30am at the Fuwa Engineering Manufacturing plant while a large number of workers were inside, according to the Southern Metropolis News . Witnesses said they heard three blasts as the plant’s roof was blown off and windows shattered, the report added. The windows of other factories were also broken in the blast up to 100 metres away, it said. The factory has been sealed off, with several fire trucks at the scene. The injured workers have been sent to three local hospitals for treatment.