A massive explosion at the Haoye Chemical Co Ltd plant in north China Sunday morning left five people dead and eight missing.

Thirty others were injured by the blast just outside of Panjin, which has closed the company's entire oil refinery and chemical complex. Reports indicated that the plant could be closed for several months.

Fire crews had the blaze under control. The air quality in the area of the plant was being monitored.

The cause of the explosion was under investigation.