Investigations are underway after a fire broke out at the derelict Kirk Street flats in Peterhead early on Sunday morning.
Fire crews from Peterhead, Fraserburgh, Ellon and Maud were called out to the scene at around 1.40am.
Firefighters in breathing apparatus worked on different sectors of the disused block of flats and used two main jets and two hosereel jets to extinguish the blaze.
They also used thermal imaging cameras, PPV (positive pressure ventilation) fans and small tools.
The last appliance left the scene at 6.15am.
The fire is believed to have started on the first floor of the building but it is unknown if it was started deliberately.
Currently the cause of the blaze is unknown but enquires will be made to establish exactly what happened and whether the incident will be treated as suspicious.
The Kirk Street flats have been unoccupied since 2005 following the closure and demolition of the Kirkburn Mill.