Seven people were injured in a fire at a chemical plant in East China's Zhejiang province, local sources said Monday.

The fire engulfed the three-story New Oriental chemical plant in the province's city of Taizhou at approximately 3:05 am after an explosion took place inside the plant.

Seven workers were injured in the first, with four remaining in serious condition. The workers are being treated at a local hospital.

The fire was put out two hours after igniting and the cause of the explosion is under investigation.