LONDON (AP) — Firefighters in Northern Ireland are spending a second day batting fires across difficult terrain on the Mourne Mountains.

More than 70 firefighters and 10 fire trucks from across Northern Ireland were involved Saturday in trying to contain the wildfire, while helicopters from both Britain and Ireland are set to join the effort.

The wildfire has been raging since Friday morning in the Slieve Donard area — the highest point in Northern Ireland, with a peak of 850 meters (2,780 feet).

The Northern Ireland Fire and Rescue Service has urged people to stay away from the area as it declared a “major incident."

Northern Ireland's first minister, Arlene Foster, said the wildfire is “devastating and tragic," adding that the impact on local wildlife and flora is “unimaginable.”

Assistant Fire Commander Aidan Jennings said the cause of the wildfire is unknown at present but noted they are “predominantly caused by human behavior.” He said firefighters are wearing personal protective equipment and travelling for up to an hour and a half to get up the slopes.

“We’re working with small pumps out of rivers but predominantly it is a physical, hard, beating-out job up there," he said.

He said the fire was moving quickly, pressed by an easterly wind. The weather has been relatively dry in recent weeks.