Fire crews are continuing to try and control the spread of the flames A Lancashire Fire and Rescue Service spokesman said: “The area affected is approximately 1km square in size.”Firefighters are tackling the fire from three locations using specialist wildfire fighting equipment plus hose reels and beaters.”Mountain rescue officers and United Utilities are assisting at the incident.”Crews remained at the scene on Friday morning as they continued to tackle the smouldering fire. Good Morning from Winter Hill, Bolton. Deployed at 03:45 to support @CumbriaFire , @LancashireFRS and @manchesterfire 🚒☀️🔥 #moorlandfires #999Family— Carnforth Fire (@Carnforth_Fire) June 29, 2018 Dave Saxon, director of operations at Tameside Council, said the local authority was monitoring air quality, which had improved on Thursday, and there had as yet been no increase in GP appointments or attendance at A&E.Cause of England’s biggest wildfire is probedFire chiefs say they are “not confident” of finding out how the Saddleworth blaze – the worst biggest wildfire in living memory – began, given the size of the blaze, but there was no evidence it had been started by BBQs or off-road bikers.Around 10 fire engines, along with specialist vehicles, helicopters, mountain rescue and Army trucks, are now deployed at Swineshaw Reservoir, Stalybridge, as an operating base.Video: Saddleworth fire seen from drone Fire crews working to control the spread of the flames on Winter Hill on Thursday nightCredit:Danny Lawson/PA Huge plumes of smoke could be seen from the area surrounding the moorland. Smoke emitted from a fire on Winter Hill near Bolton If the fire worsens, GMFRS will be able to call out an RAF Chinook helicopter, based at RAF Odiham, Hampshire.It would be used to lift a high-volume pump, capable of pumping 7,000 litres of water a minute, to pump water up on to the moors. Video: Huge blaze engulfs Saddleworth Moor The spokesman said there was no immediate risk to livestock, domestic properties or infrastructure but residents were warned to keep doors and windows closed.Army helps tackle Saddleworth Moor fireSpeaking about the Saddleworth blaze, Tony Hunter, assistant chief fire officer of Greater Manchester Fire and Rescue Service (GMFRS), said there had been a “significant effect” on the fire in the past 24 hours and work was continuing with the help of the Army.”We have made significant improvements but I would put an air of caution there though, we had a similar occasion yesterday where we thought we were on top of it and it flared up.”Mr Hunter cautioned that while the fire was now “contained and under control”, he said “things can develop” and if the wind blows the flames back on to the moors, it will act as a “fuel source” for the fire. Smoke billows from the fire on Winter Hill, near BoltonCredit:Danny Lawson/PA A series of “apocalyptic” wildfires on the Pennine moors could take weeks to put out, the fire service has warned, after a second major blaze broke out just 30 miles from a fire that has raged for days.Seven square miles of Saddleworth Moor has gone up in flames, blanketing the Greater Manchester region and beyond in smoke and ash. Fire chiefs are considering setting fire to Saddleworth to create brakes to stop the out-of-control blaze, amid fears that trapped industrial pollution in the peat could be released into the air.Scottish soldiers from the 100-strong A Company of the 4th Battalion, Royal Regiment of Scotland, known as the Highlanders, have joined more than 100 firefighters who have been battling the blaze since Sunday, leading to a “significant improvement”.Meanwhile, a new moorland blaze – on Winter Hill, near Rivington, Lancashire – broke out on Thursday with huge plumes of smoke visible from the area surrounding the moorland.Fifteen fire engines from Lancashire Fire and Rescue spent the night on the moors preventing the fire, near Bolton, from spreading further. He said the operation could last for weeks before the fire burns itself out, though the Army deployment is for an initial 48 hours.Mr Hunter said a good downpour of rain was needed to saturate the dry ground and vegetation – but none is forecast for days as the heatwave continues. Blaze was ‘towering inferno… very apocalyptic’Pete Woodward, whose home backs on to the hills just 22 yards (20m) away, spent the night at his brother’s home nearby after being evacuated on Tuesday evening.Mr Woodward said: “I got back to the house last night to a towering inferno behind, very apocalyptic in view, and it was quite scary but exciting at the same time.” Seven fire engines from Greater Manchester initially went to the scene, along with five from Lancashire Fire and Rescue Service, when the fire started shortly before 3.30pm.The Manchester crews were later replaced by more Lancashire crews. Major Phil Morgan, commanding the Army detachment, said: “We meet every challenge and commit 100 per cent in what we do.”Currently we have broken our boys down into various locations and we are beating the fire with paddles and we are supporting them by moving equipment, we are putting water on the fires and we are doing everything we can to stop this fire at the moment.”We are truly really happy and excited to be here and the boys are cherishing every moment of it.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily  Front Page newsletter and new  audio briefings.