An explosion at a chemical plant in China's southwestern province of Sichuan has killed 19 people and injured 12, the local government said on Friday. It is not yet clear what caused Thursday evening's blast at Yibin Hengda Technology in an industrial park several hours distant from the provincial capital of Chengdu, authorities in Jiang'an county said in a short statement. Photos on Chinese social media showed a huge fire and plumes of smoke rising from the facility. China has been 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.