The PSNI is treating an overnight fire at a school near Stormont as arson.
The fire at Cabin Hill School near Stormont on the Upper Newtownards Road was discovered by the caretaker shortly before 1.00am.
Two disused buildings were alight when fire fighters arrived and it took crews from six appliances to tackle the blaze and stop it spreading to the main school buildings.
A police spokesman said initial examination of the scene indicated the fire was started deliberately.
A new £4 million school building was built a few years ago and the old property - which served as the home of the First Prime Minister of Northern Ireland for a period in the 1920s - was earmarked for development.
Michael Graham of the Fire and Rescue Service said: "When we arrived we found two larger derelict buildings well alight and we had concerns the fire may spread to further school buildings.
"We has six appliances there and were quickly able to get the fire under control and stop it spreading."
PA