The world’s worst underground coal fires are in Inner Mongolia. Some have been burning for 50 years. The amount of coal being burned is estimated to be about 20 million tonnes a year.

The Inner Mongolia regional government has now announced plans and financing of 200 million yuan ($au36 million) to begin extinguishing the fires.

According to the plan, half of the fires could be extinguished by 2012 simply by digging coal out of the path of the fires and covering the fires with sand.

The government said that the fires were caused by "improper mining practices" and "dry weather" but did not explain why it has taken 50 years to produce a plan to put them out.

Collapsing coal seam burning in an open pit mine in the Rujigou coalfield in China.