A major incident has been declared after two new rapidly developing and aggressive moorland fires merged together.
Greater Manchester Police have warned pedestrians and motorists to avoid Winter Hill and Scout Road near Bolton after two blazes combined as a result of increasing wind speed.
The Winter Hill blaze started on Thursday near a major TV transmitter and currently covers about 1.9 square miles.
A 22-year-old man from Bolton was arrested on Friday on suspicion of arson with intent to endanger life.
Lancashire Fire and Rescue Service said 10 crews remained on the scene overnight, but the number was increased to 22 from 4.30am on Sunday.
Greater Manchester Fire and Rescue Service said on Saturday it had 28 fire engines tackling the moorland fires.
There were approximately 120 personnel on the moors, split between seven areas of wildfire in Tameside and Winter Hill, Bolton.
The first moorland fire – on Saddleworth Moor – started on Sunday amid Britains heatwave and has devastated surrounding land around Carrbrook.
Assistant chief fire officer Dave Keelan said: This is an exceptionally challenging time and I am proud of the hard work and brave commitment of our firefighters.
Lancashire fire service area manager Tony Cook said very intensive firefighting is taking place on Winter Hill, including personnel doing shuttle runs in appliances to get water to the scene while others manually try to beat the fire out.
Fire break trenches are also being dug to try to protect local buildings.
About 100 soldiers from the 4th Battalion, Royal Regiment of Scotland, were sent from their Yorkshire barracks on Thursday to aid firefighters in Saddleworth for an initial 48-hour deployment.
Their presence has been extended until Monday afternoon following a request by Greater Manchester mayor Andy Burnham.