Six people have been hospitalized and hundreds of firefighters deployed to battle a blaze sparked by an explosion at a plant in southern China that produces the toxic chemical paraxylene.

Authorities say there have been no chemical leaks due to the blast Monday evening at the Goure PX Plant in Zhangzhou, Fujian province — the second explosion to hit the factory in 20 months.

Paraxylene, or PX, is used for making fibers and plastics. Concerns over the safety of PX plants have prompted several protests in China in recent years.

Zhangzhou Deputy Mayor Zhang Yiteng told reporters one person was injured at the blast site and an additional five hurt by broken glass.

The Xinhua news agency says strong tremors were felt up to 50 kilometers (30 miles) away.