Firefighters are continuing to battle a blaze on Machen Mountain which has left an area the size of 50 rugby pitches scorched.

The fire broke out on the Crosskeys side of the hill on Saturday night, before the Machen side set alight on Sunday morning. The fire continued until Monday morning, before it started to spread again on Monday afternoon.

By Monday night, the hillside glowed orange once again and residents living nearby were warned to close their windows and doors, with a large cloud of smoke lingering in the air over Machen.

Some residents have reported falling ash in their gardens in recent days due to the fire.

The South Wales Fire Service has said it believes the fires were caused deliberately.

Residents rallied around the firefighters on Monday, and took it upon themselves to bring them snacks, water and fizzy drinks to help them with their efforts.

Children even ordered pizzas to bring up to the firefighters, many of which had been working long hours trying to keep the flames at bay.

In a statement issued at around 11.15 on Tuesday morning, the fire service said: “Firefighters remain at the scene on Machen Mountain this morning following a series of suspected deliberate grassfires.

“Multiple reports of fires on the mountain were received over the weekend, with crews using specialist equipment in difficult terrain to tackle the flames – which have now spread over 50 hectares of grassland.

“Multiple fire service vehicles have been in attendance including deployment of a firefighting helicopter, fire engines, off-road vehicles and the service’s Wildfire Units. This morning Natural Resources Wales (NRW) has provided heavy plant machinery to create fire breaks to stop the fire spreading down the mountainsides.

“We would also like to say a special thank you to the local residents who supported us throughout, even offering our firefighters tackling the blaze water and snacks.”

The fire service revealed it had received more than 420 calls about fires on the mountain since Thursday, and has attended more than 160 grassfires, suspected to be deliberate, across south Wales in the last week.

The statement continued: “Wildfires impact our communities across Wales and draw fundamental and valuable resources away from our communities, placing unnecessary risk on lives.

“The impact of grass fires is devastating on the environment killing animals and destroying wildlife habitat as we have already seen in multiple areas across south Wales.

“We will continue to work with our communities to reduce the risk and impact of grass fires, however we would remind people to please refrain from the use of any open flame fires in such areas to reduce the risk of fires starting and spreading due to the increased warm and dry weather.

“Once again we would urge anyone who has information on grass fires, or who sees anything suspicious to contact 101 or call Crimestoppers anonymously on 0800 555 111.  If you see a grass fire, or anyone starting a grass fire, please call 999 immediately.”

Meanewhile, Peter Cloke, Land Management Team Leader at NRW, said the fire “caused extensive damage to our woodlands and has destroyed thousands of pounds of newly planted young trees”.

He added: “The firefighting helicopter contracted by NRW was deployed to support South Wales Fire and Rescue in their efforts.

“People who deliberately set grass fires are risking people’s lives as well as endangering wildlife and causing a considerable cost to the taxpayer.”