Five people were killed while three others were injured in a factory blast in south China's Guangdong Province, said local sources on Friday.

The blast happened at 5:10 p.m. Thursday in the Zhenbang Metalwork Co., Ltd in Zhongshan city, when technicians and workers were installing and testing spray painting equipment. Three people were killed on the spot while two others died in hospital.

Another three injured persons were transferred to the Zhongshan People's Hospital.

Work safety administrative authorities said that the accident happened when the equipment was used in inflammable gas.

But cause of the accident was still under investigation.