BEIJING, China » Safety officials say a gas explosion from a coal mine in southwest China has killed 19 miners.

The State Administration of Work Safety reports on its website that the blast occurred after midnight Friday in Guizhou province’s Liupanshui city.

It says 15 workers escaped and all the bodies have been recovered. An investigation is under way.

Such explosions are usually caused by the ignition of methane and other gasses that accumulate in the shaft because of poor ventilation.

China’s coal mines are the world’s deadliest with thousands of miners killed annually. Demand for coal induces many producers to sidestep safety regulations, although conditions have improved and a number of small, illegal mines have been shut.