Families have been forced to leave their homes after a large blaze broke out on a mountain.

Some 20 properties in the mining town of Blaenau Ffestiniog, Gwynedd, have been evacuated after the fire broke out on Monday night.

The blaze is thought to have started behind quarry workings in an area overlooking the town called Garreg Ddu - Black Rock.

Eyewitness Chris McPhail said described it as looking "like a volcano".