The Northern Ireland Fire and Rescue Service (NIFRS) has confirmed it is treating a fire on Black Mountain in Belfast as deliberate.
Shortly after 3pm on Monday it was reported that a large grass area on the mountain was on fire.
One fire appliance from Springfield Fire Station was dispatched to the scene and firefighters used three fire beaters to extinguish the blaze.
The incident was dealt with by 4pm and a NIFRS spokesperson said they believe the fire was started deliberately.
Sinn Fein MP Paul Maskey said Black Mountain is one of Belfast's "greatest assets" and urged the public to treat it with respect.
“In normal times, thousands from west Belfast and further afield flock to enjoy the mountain on a weekly basis. Families, walkers, runners and cyclists regularly adorn it’s hills and pathways," he said.
“The spectacular views across Belfast, Antrim and as far as the Mourne Mountains are like no other. The mountain is also home to a rich and varied wildlife."
Mr Maskey said he was "saddened" to see a fire on the mountain and hit out at those who may have been behind it.
“We cannot be certain of the cause of the fire, but I want to appeal to you all to please respect our environment. Starting a fire is not good fun, it is not a bit craic and it is most definitely not harmless," he said.
“It destroys our local environment and natural habitat for wildlife. It is also a waste of the fire services time.
“We are blessed to have the black mountain on our door step. Let’s cherish it, love it and do all that we can to preserve it.”