HOHHOT, April 24 (Xinhua) -- Four people were confirmed dead, and 35  injured after an explosion in a chemical plant in north China's Inner Mongolia Autonomous Region early Wednesday morning, local authorities said.

The blast happened at 2:55 a.m. in a workshop of the Dongxing Chemical Co. Ltd., a subsidiary of Inner Mongolia Yidong Group Corp. Ltd. in Zhuozi County in the city of Ulanqab.

An investigation team said firefighters have properly handled the explosion scene and isolated a tank nearby the explosion spot. The fire has been put under control.

The authorities said that residents around the plant have been evacuated. Local health departments have provided medical care for the injured. All injured people are in stable condition.

The local ecology and environment department has started to monitor the air and water quality.

An investigation is underway.