HOHHOT -?One was killed and 6 others injured in a blast-triggered fire on Thursday at a chemical plant in North China's Inner Mongolia Autonomous Region, local authorities said.

Another man was still missing in the blast, which occurred at 10:50 am at a workshop of Inner Mongolia Yihua Chemical Industry Co, Ltd, located at the Wuda District in the city of Wuhai, said a spokesman with the district government.

"The fire is under effective control," he said.

Initial investigation showed improper operation by the workers was mainly attributed to the blast.

The injured were receiving treatment at a local hospital and further investigation is under way.