Two people were killed and another 12 missing after an explosion at a refinery and chemical plant in northeast China, state media reported on Monday.

The explosion occurred on Sunday afternoon at Panjin Haoye Chemical, while workers were carrying out maintenance work at an alkylation facility.

Panjin Haoye is an independent refinery and chemical producer in the city of Panjin in Liaoning province.

Thirty people were also lightly injured, according to the CCTV report.

"The fire is currently under control and the remaining flames are in a stably burning stage," CCTV said.

Videos and photos published by CCTV showed a cloud of thick smoke and flames rising from the factory, and a group of firefighters in helmets outside the plant.

CCTV said more than 330 firefighters had been dispatched to fight the blaze. (Reuters/AFP)