Smoke and fire damage was caused to a block of flats in west Belfast after a sofa was set on fire in a communal area of the building.
Police are treating the fire at Ross Street as arson.
No one was injured in the incident.
The fire broke out in the early hours of Tuesday (12 May).
Detective Sergeant Natalie Moore said the fire, which was extinguished by NIFRS, was reported to police shortly after 1.30am.
“Thankfully, there were no reports of any injuries.
“Clearly, whoever is responsible has no respect for the community or any regard for the valuable police resources that were diverted away from other community priorities to deal with this incident.
“Enquiries are ongoing and I want to encourage anyone who noticed any suspicious activity in the Ross Street area or who has any information which may be of assistance to our investigation to contact detectives in Musgrave on 101 quoting reference 128 12/05/20. Information can also be given anonymously through the independent charity Crimestoppers on 0800 555 111,” she added.