The incident took place at 07:50 p.m. (11:50 GMT) on Wednesday at Xumei Biotech Co. Ltd., located in the Weishi county, the Xinhua news agency reported.
Five people had died on the spot, while one more person had been hospitalized and succumbed to his wounds in the hospital, the reports, citing the local emergency management bureau, said.
The authorities reportedly detained the head of the biotech company pending the probe into the incident.
