SHANGHAI: As many as 40 people were killed while 640 sustained injuries in an explosion that occurred at a pesticide plant in eastern China’s Jiangsu province, China, media reports said on Friday.

It occurred on Thursday at the Chenjiagang Industrial Park in the city of Yancheng while the fire was brought under control at 3 am today, according to state television.

Survivors were taken to 16 hospitals with 640 people being treated for injuries. Thirty-two of them were critically injured, it said.

The cause of explosion is not known yet. Authorities said the investigation into the incident is underway.