Police are warning people not to enter the grounds of a former community hospital in Flint.
It follows an fire at the site on Tuesday which fire officers say was started deliberty.
North Wales Police and firefighters were called to reports of the fire at the Old Cottage Hospital on Cornist Road just before 2pm.
Police said no one was injured as a result of the incident and an investigation is ongoing.
A spokesperson for North Flintshire police team said:
“There have been an increase in reports of people entering the grounds and building of the Old Cottage hospital on Cornist Road in Flint.
This building has been unoccupied for quite some time and is in a very poor state of repair.
As tempting as old buildings such as this one are to explore, they are unsafe, please do not enter the grounds or the building.”
A spokesperson for North Wales Fire and Rescue Service said:
“We were called to reports of a fire at a derelict building on Cornist Road.
The cause was deliberate ignition and there was two square meters of fire damage.
We used two breathing apparatus and one hose reel jet to extinguish the fire.”
Police have asked the public to contact them on on 101 “if you see any suspicious activity at the location.”
Flint Cottage Hospital closed in 2013 after serving the town for more than 100 years.