A huge coalfield with 23 billion tons in reserve has been discovered in Xinjiang Uygur autonomous region, said its Department of Land and Resources.

The reserve is equal to ten times China's current annual coal demand, which is expected to reach 3 billion tons in three to five years.

The coalfield, about 800 m underground, covers an area of more than 300 sq km in Shanshan county in the Turpan Basin.