An explosion at a coal mine in southern Poland has killed at least 12 workers.

Thirty miners were injured, 15 of them seriously. Twenty-nine others emerged unharmed. The methane explosion occurred at a depth of over 1,000 metres near the city of Katowice. It is Poland's worst mining accident since November 2006, when an explosion left 23 miners dead.

(Photo Flickr / Ahorcado)