A number of residents were evacuated from their homes in Lurgan on Wednesday afternoon, following an arson attack on a property.
Police said the incident happened in the Hill Street Area of the Co Armagh town at around 2.45pm.
No one was inside the property targeted by the arson, with the blaze extinguished by the Northern Ireland Fire and Rescue Service.
They said a number of nearby properties had to be evacuated during the incident and residents were only able to return to their homes after the fire was brought under control.
A police spokesperson said: “Enquiries are continuing to establish the circumstances surrounding the incident but at this stage, the fire is being treated as deliberate ignition.
“Police would appeal to anyone who witnessed anything suspicious in the area at the time of the incident to contact detectives on 101, quoting reference number 1162 21/07/21.
“A report can also be made online using the non-emergency reporting form via http://www.psni.police.uk/makeareport/ . You can also contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org/.”