A major blaze in the Mourne Mountains is believed to have been started deliberately, NI Fire and Rescue Service has said.
In a statement, it urged the public to take more caution when lighting fires outside.
The fire on Northern Ireland’s highest mountain Slieve Donard led to a three-day emergency effort involving more than 100 firefighters.
It was brought under control on Sunday evening.
Area Commander Mark Smyth said he was “angry” the fire may have been started deliberately.
Mr Smyth pleaded for “people to stop lighting fires – especially over the next weeks and months”.
“A big issue for me is we have firefighters down the mountains when we really need them in towns where there might be some extremely serious life risk fires or there might be RTCs [road traffic collisions],” he told the BBC’s Good Morning Ulster programme on Monday.
“That’s the first thing that is major for us and our resourcing.
“But then whenever you see pictures of firefighters that we have they are absolutely exhausted, but they will keep going.
“I am extremely disappointed in whoever thinks this is fun or if they think this is a great opportunity to manage land.”
The gorse fire was declared a major incident on Saturday and there has been extensive damage to wildlife and the environment.
The Northern Ireland Fire and Rescue Service (NIFRS) said the fire is no longer considered a major incident.
More than 100 firefighters were involved in the operation.
Two groups normally get the blame following situations like this – landowners and recreational users of the uplands.
Burning of vegetation is a recognised way of managing land.
There are strict rules around it and a designated season for it which has now passed.
Huge numbers of people have also been using the mountains during lockdown.
It’s estimated there’s been three-to-four times the normal footfall in the mountains.
That’s several hundred thousand people in the year.
One carelessly-discarded barbecue or poorly-extinguished camp fire would have been enough to start this devastating blaze.
In a statement on Monday, NI Fire Service’s chief fire and rescue officer Michael Graham said firefighters had worked in “intense conditions” to stop the fire “spreading to threaten human life or property”.
“While I am proud of the work our people did, we are all saddened by the destruction this fire has caused to our natural environment.”
He said that firefighters had been involved in responding to 400 other incidents while the fire on the Mourne Mountains was burning.
Mr Graham thanked everyone in the fire service for their efforts in fighting the blaze, and said it had “simply lost track of the number of people who contacted us offering anything they could to help us”.
“For everyone out there who watched the fire this weekend with horror, there is one thing we ask of you – help us prevent these fires starting in the first place,” he said.
“Don’t start fires in the countryside. Don’t be careless with smoking materials or glass. Don’t be careless with barbeques or any other flames.”
Agriculture Minister Edwin Poots said it was “shockingly sad” that extensive damage had been “done to an area of outstanding natural beauty”.
“Whoever lit this fire – whether it was accidental or whether it was reckless – should be thoroughly ashamed of themselves, because this involved some element of human behaviour,” he added.
“It is so easy for this to happen, it happens dozens of times every year, this one was very visible to the eye, there were major fires last year on the Antrim Plateau and other places, so this happens every year and we really need people to be very, very careful, very conscious of the fact that fires are so easy to light in these areas right through from March to June.”
Mr Poots said he was committed to looking at legislation that would impose major penalties on anyone found guilty of starting such fires.
“If we are required to upgrade our legislation then that’s something I will not be shy in bringing forward,” he said.
Later on Monday, Mr Poots said the fire was now under control but it would take decades for plant and animal life to recover from the damage caused.
He told the assembly that there would be a long-term loss to biodiversity, with the damage extending to more than 3.5km.
Mr Poots said the risk of wildfires had always existed but in Northern Ireland they were rarely natural.
“They are almost always started either deliberately or by reckless burning of inflammable vegetation or material,” he said.
“We need to think about all measures that can be put in place to deter people from starting such fires.”
The minister said that in 2020, Forest Service staff attended 22 fires. As a result of these, 70 hectares of forest and 110 hectares of peatland was burnt, he added.
Sinn Féin MP for South Down, Chris Hazzard, said the fires made him feel “sick to the stomach”.
“The Mournes on Friday night looked like a range of volcanoes erupting.
“We had messages coming in from as far away as Australia and from America and Canada, people who had travelled here previously and enjoyed this local area who were just completely shocked.”
Mr Hazzard welcomed Mr Poots’ comments that he was committed to looking at legislation in relation to major penalties and said “greater action” was need.
“The fire service says that they were dealing with this from the very early hours of Friday morning, likely to be 05:00 or so,” he said.
“There’s not too many people who go into the Mournes at 05:00 on a Friday morning for a barbecue.
“What we need to see now is a moratorium on all gorse burning right across the island.”
National Trust director for Northern Ireland, Heather McLaughlin, said it would take years to repair the damage caused by the gorse fire.
Speaking to BBC Radio Foyle, Ms McLaughlin said she “found it personally devastating” looking out at a landscape of 500-600 acres of scorched earth.
She said the people of Northern Ireland “have lost a large asset” as a result of the fire, and a lot of wildlife would be detrimentally affected because of it.
“So many Skylarks and Meadow pipits were out flying around yesterday trying to find their nests – their young are gone,” she said.
“We have lost all those eggs and probably many other species we don’t know, like lizards or newts that people probably don’t see, but they are all absolutely vital to the ecosystem here.”
Ms McLaughlin said she hopes this incident will hopefully see the introduction of harsher legislation for anyone who deliberately starts these sort of fires.
“Hopefully, if there is someone responsible for this, they are morally struggling with themselves this morning,” she said.
“I am very cross and very disappointed with whoever has done this.”
Assistant Chief Fire and Rescue Officer Aidan Jennings said the location, terrain and weather conditions continued had presented many challenges.
He said the location, terrain and weather conditions continued had presented many challenges.
“Everyone has worked so hard in extremely challenging conditions, they have worked tirelessly – it is at the heart of what it means to be a firefighter,” he said.