Firefighters have returned to the Mourne Mountains for a third day tackling a major blaze.
More than 100 firefighters and 12 appliances fought the flames across challenging terrain on Saturday.
Teams returned to the Co Down peaks at 6am on Sunday.
Their efforts have been supported by police, Coastguard, Mourne Rescue Team, Forestry Service, National Trust, NIEA and Sky Watch Patrol.
Coastguard helicopters from the Republic of Ireland and Great Britain allowed fire chiefs an aerial view of the blaze to help inform tactics, transport personnel to remote locations and plan resources.
The public has been urged to stay away.
Aidan Jennings, assistant chief fire and rescue officer, said it is “undoubtedly one of the most challenging gorse fires firefighters have ever had to deal with”.
He said fire crews will be available to those who need them despite the operation in the Mournes, but asked the public to be extra fire aware.
“I want to reassure everyone that we have put contingency measures in place and if you need us in an emergency we will respond,” he said.
“However, I am asking everyone to be extra fire aware at this time both in your home and in particular in the countryside.”
Environment Minister Edwin Poots said local people and businesses have been sending food and refreshments to those battling the fire.
The blaze in the Slieve Donard area started in the early hours of Friday.
The Northern Ireland Fire and Rescue Service declared a major incident on Saturday.
There is no indication yet of how it started.
Dramatic images of the mountains ablaze sparked concern, with First Minister Arlene Foster tweeting: “This is devastating and tragic. The impact on wildlife and flora is unimaginable. Full support to those battling the flames.”
Deputy First Minister Michelle O’Neill voiced “huge admiration” for the firefighters and all responders.
On Saturday the flames spread from Bloody Bridge, across Thomas Mountain and the base of Slieve Donard, as well up Northern Ireland’s highest peak to less accessible ground.
On Sunday the focus of firefighting efforts were in the Bloody Bridge area following overnight winds.