Harrowing photos show the inferno – about the size of one-and-a-half football pitches – as it ripped through the moors near Diggle, Greater Manchester.
The blaze on Marsden Moor, off the A62 Manchester Road, began around 7.30pm and 20 firefighters from West Yorkshire and Greater Manchester are currently battling the flames.
Many people close to the blaze took to social media to share their concerns as the fire continued to spread across the grassland.
One driver tweeted: “Just coming up the road from Marsden and this is the apocalyptic scene at the crossroads. You can feel the heat through the windscreen.
“I hope our intrepid firefighters stay safe.”
Another wrote: “Never seen anything like this, had a drive up as these things look terrible…high up on the Pennines between Saddleworth and Marsden on the Manc/Yorks border but close to houses, including two pubs. Hope it is contained.”
The road between the Colne Valley and Diggle is currently closed in both directions to protect the public, according to local reports.
The closure is in place from Mount Road, near the Carriage House pub to the former Great Western pub.
“Never seen anything like this”
Greater Manchester Fire and Rescue Service warned residents to keep windows closed due to the smoke and advised drivers to avoid Hill St Welbeck St South and Bentinck St.
A massive blaze swept across Saddleworth Moor in the summer, which covered thousands of acres.
More than 150 people who lived in close proximity to the fire were ordered to evacuate their homes.
Wildlife expert Dave O’Hara, site manager for RSPB Dove Stone, said the effects of the fire could last for 15 years.