Fire crews have been battling a huge mountain blaze which has seen around 20 homes evacuated overnight in North Wales.

The alarm was raised at around 8.30pm on Monday after flames were spotted at a slate quarry above the town of Blaenau Ffestiniog, Gwynedd.

Blaenau Ffestiniog fire
The mountain fire in Blaenau Ffestiniog (Janine Hill/PA)

On Tuesday morning, North Wales Fire and Rescue Service said crews were still battling the blaze at the Llechwedd slate quarry, which they had yet to get under control.

Four fire engines and an aerial ladder platform have been in use, while police have closed a street below the burning mountain.

Blaenau Ffestiniog fire
Around 20 homes were evacuated overnight (Ceurwyn Williams/PA)

North Wales Police said in a tweet: “From the roundabout in Blaenau Ffestiniog to McColls on Church Street due to Fire on the mountain.

“Diversions in place but please avoid the area if possible.”

The town of Blaenau Ffestiniog was developed in the 19th century to support the slate quarrying at several sites in the area, most of which have now closed.

The Llechwedd quarry has still produced slate on a limited scale in recent times and now houses a visitor attraction.