Chinese officials say at least 27 workers are confirmed dead after a gas explosion tore through a coal mine in China's northwest Shaanxi province.

China's official Xinhua news agency says 39 miners were working at the Wayaobao mine in Zichang county when the blast happened Saturday. Five workers remain missing. Seven miners escaped with minor injuries.

China's mines are the world's deadliest. Thousands of workers are killed each year in fires, explosions, floods and cave-ins, despite government efforts to improve safety.