A second blaze has broken out on moorland in West Yorkshire on one of the hottest days of the year.
The fire on Marsden Moor is believed to have been started by a barbecue at Easter Gate, the National Trust said.
Eleven crews from West Yorkshire Fire and Rescue are at the scene trying to get the flames under control.
Firefighters also remain on Ilkley Moor, damping down at a fire which started on Saturday and spread over 25,000 sq metres of moorland.
Three men aged 19, 23 and 24 have been arrested over that blaze and remain in custody.
The Marsden Moor branch of the National Trust said it was the sixth fire on its moorland this year, and this one was covering about 3 sq km of land.
The last significant fire was on 27 February, with four separate smaller fires reported since.
The trust said the moor is a designated Site of Special Scientific Interest, a a Special Protection Area and a Special Area of Conservation due to the ground-nesting bird population and blanket bog habitat.
It said a helicopter has been deployed since 09:00 to take water from nearby reservoirs to the fire.
“At present it is estimated that an investment of more than £200,000 in restoring this special habitat has been lost,” the trust said.
“The deployment of the helicopter itself costs the trust, a conservation charity, £2,000 per hour.
“We’re devastated to see the destruction caused. Please help us protect the moors and wildlife by calling the fire brigade immediately if you spot any signs of fire.”
Greater Manchester Fire and Rescue Service is at the scene assisting crews from West Yorkshire.
It said on its Facebook page: “If you live around Stalybridge, Oldham or Rochdale and can smell the smoke please keep windows and doors shut as a precaution.”
Bradford Council is warning people to stay away from the moors while the fire is being dealt with.