A wildfire in the foothills of the Mourne Mountains was likely to have been started deliberately, police have said.
More than 50 firefighters battled the mile-long blaze at Tollymore Forest Park last night into this morning.
A caravan park and several homes on the Tullybrannigan Road outside Newcastle were evacuated after the blaze was reported at around 8.30pm yesterday.
Guests at Bonny's Caravan Park were evacuated but have since been allowed to return.
Several buses were used to evacuate holiday-makers and residents.
Detective Chief Inspector Will Tate said: "The fire caused widespread damage and led to a number of evacuations, including from a nearby caravan park.
"Our colleagues in the Northern Ireland Fire and Rescue Service have now determined that it is likely that the fire was started deliberately and I am appealing to people to assist us in our investigation.
"Anyone with information or who may have seen something that could be useful to investigators, please contact us on 101."
Current scene of the large fire at Tollymore Forest in Newcastle. Emergency services are dealing with the incident.
— goQradio (@goQradio) April 21, 2019
Please avoid the Tullybrannigan Road & Bonny’s Caravan Park. pic.twitter.com/cKW1Aiwtpt
NIFRS group commander Eddie Carroll told the BBC the fire spread rapidly due to the wind.
"We use a term in the fire and rescue service called crowning, when the fire was jumping across the top of these very high areas of gorse, and the fire was moving at a very rapid rate, and our crews were concerned when they were trying to deal with this," he said.
"That then presents very serious difficulties for us because the fire is very high up and it can spread very quickly."
Update on fire at Tollymore forest, Newcastle. Please be careful & vigilant. #Newcastle pic.twitter.com/mfyvoiKaxQ
— Alicia V. Perry? (@aliciavperry) April 21, 2019