An arson investigation is under way after a major grass fire tore its way across a hillside last week.

Emergency services were called to a reports of a grass fire on Llangynidr Mountain on the evening of Wednesday, March 23.

Crews from both Mid and West Wales Fire and Rescue Service and South Wales Fire and Rescue Service were deployed to the scene to tackle the blaze.

The four-mile wide fire was contained by emergency services, who used an array of equipment and vehicles, including a helicopter, to hold off the blaze and prevent danger to people or damage to property. The crews, who were working on difficult terrain, extinguished what they could to minimise damage before the fire was contained and allowed to burn out.

The fire service has since established that the blaze was started deliberately and confirmed the fire is being treated as arson. The case has now been passed on to Gwent Police to investigate.

A spokesperson for Gwent Police said: “We received a report of a grass fire in Llangynidr, near Tredegar, at around 8.40pm on Wednesday, March 23.

“A section of land was set alight and officers from the South Wales Fire and Rescue Service has confirmed that the fire was deliberately started.”

Police enquiries are ongoing and anyone with information should call 101 or send Gwent Police a direct message on social media, quoting log reference 2200096335. You can also call Crimestoppers anonymously on 0800 555 111.

The fire service was first called to the scene on Llangynidr Mountain shortly before 8pm, after receiving calls reporting a large grass fire on the hillside. Images of the fire and its billowing smoke began to circulate on social media that evening, with witnesses expressing concerns for the welfare of people and property, as well as the area’s wildlife.

A spokesperson for South Wales Fire and Rescue Service said: “At approximately 7:50pm on Wednesday, March 23 2022, we received reports of a grass fire on Llangynidr Mountain.

“Firefighters from Ebbw Vale attended and assessed the fire and ensured further spread was prevented by a fire break.

“A stop message was received at approximately 8:41pm.”

Emergency services had earlier that same day dealt with a grass fire on common land near Rhayader.

Crews from Newtown and Llanidloes were called to Cwmdauddwr Common on Wednesday afternoon to tackle the blaze.

Plumes of smoke were seen rising over the mountain road, which connects Rhayader to Aberystwyth, before the fire was extinguised by firefighters.

If you see a grassfire, please contact 999. If anyone has any information on people causing deliberate fires contact Crimestoppers.