Arsonists have reportedly been spotted by authorities trying to start new blazes in Lancashire close to an area of moorland where a large wildfire continues to burn.

A police helicopter is understood to have seen a group of people attempting to light fires at a grassland called Healey Nab, just four miles away from Winter Hill, where firefighters are currently tackling a huge blaze.

Tony Crook, from Lancashire Fire and Rescue Service, told Sky News the incident was “absolutely heart-breaking and unbelievable.”

"Unbelievably, just the other side of the reservoir, there is a fire developing in that location,” Mr Crook said.

He described that as the helicopter had flown over the moors, it had seen people “actually lighting fires”.

“Police are now attending that scene, to try to apprehend those arsonists,” he added: “It absolutely astounds me.”

More than 120 firefighters on Sunday launched a “large scale attack” against the wildfire, which has been raging on nearby Saddleworth Moor for more than a week.

A major incident was declared on Saturday after two huge fires already burning on the moor merged due to high winds.

Greater Manchester Police and firefighters have warned pedestrians and motorists to stay away from the scene, while people have also been urged not to fly drones nearby due the risks posed to emergency helicopter pilots operating in the area.

“Offensive firefighting is focusing on getting water onto nearby woodland to ensure any flame flare ups don't spread to that area and we have been working with partners to secure the road and infrastructure up on the top of the hill at the mast sites,” a fire brigade spokesman said.

“We are looking into getting helicopter support later in the day to assist with getting water onto the incident ground in this area.”

One man, aged, 22, from Bolton, has already been arrested on suspicion of arson with intent to endanger life in connection with the blaze.

Saddleworth Moor fire: Greater Manchester blaze in pictures Show all 34 1 /34 Saddleworth Moor fire: Greater Manchester blaze in pictures Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Thursday June 28, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Danny Lawson/PA Wire Danny Lawson PA Saddleworth Moor fire: Greater Manchester blaze in pictures British Army soldiers of 4 Scots assist the fire fighters on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures British Army soldiers of 4 Scots assisting fire fighters EPA/Ministry of Defence Saddleworth Moor fire: Greater Manchester blaze in pictures A firefighter tackles the wildfire on Saddleworth Moor which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Thursday June 28, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Danny Lawson/PA Wire Danny Lawson PA Saddleworth Moor fire: Greater Manchester blaze in pictures Soldiers douse the wildfire AFP/Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures A helicopter fills a container with water from Upper Swineshaw Reservoir AFP/Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures Members of the 4th Battalion, Royal Regiment of Scotland join firefighters AFP/Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Thursday June 28, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Danny Lawson/PA Wire Danny Lawson PA Saddleworth Moor fire: Greater Manchester blaze in pictures A firefighter tackles the wildfire on Saddleworth Moor which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Thursday June 28, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Danny Lawson/PA Wire Danny Lawson PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Thursday June 28, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Danny Lawson/PA Wire Danny Lawson PA Saddleworth Moor fire: Greater Manchester blaze in pictures The full moon rises behind burning moorland between Dovestones and Buckton Vale Getty Saddleworth Moor fire: Greater Manchester blaze in pictures These dramatic pictures taken on Monday evening show the fire on Saddleworth Moor taking hold and sending huge plumes into the sky. See National story NNMOOR; A major incident has been declared after a huge moorland fire forced dozens of residents to flee their homes in Greater Manchester. The army is on standby to help tackle the blaze which has been raging for several days on Saddleworth Moor. Some 34 properties have been evacuated in Carrbrook, Stalybridge, while police have confirmed some nearby schools will be closed. Public Health England has urged residents to keep windows and doors shut as smoke and flames could be seen for miles. Kate MacRae / SWNS.com Kate MacRae / SWNS.com Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA Saddleworth Moor fire: Greater Manchester blaze in pictures A PCSO assists a member of the public with face mask to protect gainst the smoke on Calico Crescent, Stalybridge near to the wildfire on Saddleworth Moor. PRESS ASSOCIATION Photo. Picture date: Wednesday June 27, 2018. The fire continues to spread after the blaze was declared a major incident by Greater Manchester Police. See PA story FIRE Saddleworth. Photo credit should read: Peter Byrne/PA Wire Peter Byrne PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters on Saddleworth Moor attempt to dampen down the area to stop the spread of fire after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Wednesday June 27, 2018. The fire started on Sunday and reignited the next day amid Britain's heatwave and has devastated land around Carrbrook. See PA story FIRE Saddleworth. Photo credit should read: Peter Byrne/PA Wire Peter Byrne PA Saddleworth Moor fire: Greater Manchester blaze in pictures STALYBRIDGE, ENGLAND - JUNE 27: Fire fighters continue to tackle a large wildfire sweeping across the moors between Dovestones and Buckton Vale in Stalybridge, Greater Manchester on June 27, 2018 in Stalybridge, England. Firefighters have declared a 'major incident' as they battle the huge moorland fire which measures 6km. (Photo by Anthony Devlin/Getty Images) Anthony Devlin Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures STALYBRIDGE, ENGLAND - JUNE 27: Fire officers continue to fight a large wildfire on the moors above Stalybridge, Greater Manchester on June 27, 2018 in Stalybridge, England. Firefighters have declared a 'major incident' as they battle the huge moorland fire which measures 6km. (Photo by Anthony Devlin/Getty Images) Anthony Devlin Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Mayor of Greater Manchester Andy Burnham speaks to the media, as firefighters tackle a wildfire on Saddleworth Moor, which continues to spread after the blaze was declared a major incident by Greater Manchester Police. PRESS ASSOCIATION Photo. Picture date: Wednesday June 27, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Peter Byrne/PA Wire Peter Byrne PA Saddleworth Moor fire: Greater Manchester blaze in pictures **FREE EDITORIAL USAGE** Aerial view of the fire on Saddleworth Moor. See National story NNMOOR; A major incident has been declared after a huge moorland fire forced dozens of residents to flee their homes in Greater Manchester. The army is on standby to help tackle the blaze which has been raging for several days on Saddleworth Moor. Some 34 properties have been evacuated in Carrbrook, Stalybridge, while police have confirmed some nearby schools will be closed. Public Health England has urged residents to keep windows and doors shut as smoke and flames could be seen for miles. SWNS.com SWNS.com Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters take a break from tackling the wildfire on Saddleworth Moor. PRESS ASSOCIATION Photo. Picture date: Wednesday June 27, 2018. The fire started on Sunday and reignited the next day amid a heatwave. See PA story FIRE Saddleworth. Photo credit should read: Peter Byrne/PA Wire Peter Byrne PA Saddleworth Moor fire: Greater Manchester blaze in pictures Fire officers continue to fight the large wildfire Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Fires on Saddleworth Moor Sean Quarmby/PA Saddleworth Moor fire: Greater Manchester blaze in pictures Fire officers continue to fight a large wildfire on the moors above Stalybridge Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Fire officers outside Castle Farm Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Horses are moved through heavy smoke in Carrbrook Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures A scorched fencepost Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Handout photo from Sean Quarmby of fires on Saddleworth Moor on Tuesday night. PRESS ASSOCIATION Photo. Issue date: Wednesday June 27, 2018. A number of homes have been evacuated as fires on Saddleworth Moor continue to spread. See PA story WEATHER Hot Fires. Photo credit should read: Sean Quarmby/PA Wire NOTE TO EDITORS: This handout photo may only be used in for editorial reporting purposes for the contemporaneous illustration of events, things or the people in the image or facts mentioned in the caption. Reuse of the picture may require further permission from the copyright holder. Sean Quarmby Sean Quarmby/PA Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters on Saddleworth Moor attempt to dampen down the area to stop the spread of fire PA Saddleworth Moor fire: Greater Manchester blaze in pictures A llama sits in a field below burning moorland Getty Images Saddleworth Moor fire: Greater Manchester blaze in pictures Firefighters tackle the wildfire on Saddleworth Moor PA

Emergencies crews working to extinguish the fire are likely to be working in hot conditions with “no significant rain forecast,” throughout next week, according to the Met Office.

“The trend is for dry and very warm weather, which is far from ideal. Thunderstorms in the South West are unlikely to reach that far north,” said forecaster Helen Roberts.

“On Wednesday, there is the potential for showers in that vicinity but it could be a one-off, isolated and unlikely to hit the area.

“Thursday is similar and any showers would be isolated and fleeting.”