An explosion at a chemical plant in China has killed 19 people and injured 12, the local government said on Friday, the latest deadly industrial incident in the world's largest producer of chemicals.

It is not yet clear what caused Thursday evening's blast at Yibin Hengda in an industrial park several hours southeast of Chengdu, the capital of the southwestern province of Sichuan, authorities in Jiang'an county said.

The injured are in stable condition and an investigation has begun, state news agency Xinhua said.

The company did not immediately answer telephone calls from Reuters to seek information.

Photographs on Chinese social media showed a huge fire and plumes of smoke rising from the facility.

The fire, which broke out early on Thursday evening, was put out by 11:30 p.m., the government said in its statement.

China has kicked off measures to improve industrial safety, ramping up checks over the last year, following some high-profile incidents at coal mines and chemical plants.

In 2015, an explosion in a chemical warehouse in the northern port city of Tianjin killed 165 people. Last year a blast at a petrochemical plant in eastern Shandong province killed eight people and injured nine.