TWO gorse fires on Cave Hill and in the Mourne mountains were started deliberately, the Northern Ireland Fire and Rescue Service (NIFRS) has said.
The Cave Hill fire in north Belfast has caused about 300 square metres of damage.
Another blaze near Rostrevor Road, Rathfriland was attended by seven appliances yesterday morning.
Firefighters were also in attendance at another fire on Black Mountain, where a separate blaze was put out on Monday night.
Four fire engines were called to a blaze shortly before 4pm. They left the scene at 19:30.
The public was urged to avoid the area.
The service said it received several calls about a fire on Cave Hill on Monday night from 7.45pm onwards.
Fire crews were initially not deployed as there was no risk to life or property.
Also on Monday fire crews put out several gorse fires outside Newry.
The Rostrevor Road in Hilltown was closed for several hours but re-opened later.
The fire near Rostrevor Road, which is also thought to be deliberate, was dealt with after 11am.
Green Party councillor Mal O'Hara said he was "deeply concerned" about the impact the fire may have on wildlife and the natural environment of Cave Hill.
"Fires like this can have major implications on this finely balanced environment," he told BBC NI.
