Seventeen workers died Wednesday in a gas explosion at a coal mine in southwestern China, the state-run Xinhua news agency reported.

The accident at the Shangchang mine in Yunnan province occurred at around 2:15 p.m. when 66 workers were inside, 49 of whom managed to escape unharmed, Xinhua said.

Chinese coal mines are the most dangerous in the world, with around 3,000 deaths occurring annually due to lack of safety measures and cave-ins caused by overexploitation.

Coal supplies between 60 percent and 70 percent of the energy needs of the world's second-largest economy. EFE