Firefighters were called to Waringstown to deal with an arson incident at a derelict shed just off the main street - with residents told to close doors and windows following the discovery of asbestos.
The incident was reported at 12.18am on Friday morning.
Fire Crews dealt with a deliberate fire in a derelict single storey shed. Two appliances from Lurgan Fire Station and one from Banbridge Fire Station dealt with the call.
Firefighting operations were challenged by partial asbestos in the roof of the building.
All the necessary safety precautions were taken by firefighters, nearby residents were advised to close windows and doors and Environmental Health have been informed.
Crews continued firefighting operations until 5am and as anticipated due to the nature of the fire were called to return again before 9am to deal with smouldering material inside the building.
As the building is unsafe to enter at present one Fire Crew is remaining on standby at scene.