Twenty firefighters have been tackling a blaze which is said to have destroyed three homes.
Emergency services were called to the fire in Albert Road, in the Govanhill area of Glasgow, at around 6.30pm on Thursday.
The blaze is thought to have broke out in the roof space of the sandstone building, which is made up of a block of four flats.
It is understood only three of the properties were occupied at the time, however no one had to be rescued and there were no reports of any injuries.
A spokesman for Strathclyde Fire and Rescue Service said the properties had been "extensively damaged" and that the roof had started to collapse.
A fire investigation team attended the scene and is expected to return tomorrow to carry out a full inquiry into the cause of the blaze.
Glasgow City Council said Cathcart Road was closed in both directions between Dixon Avenue and Queen Mary Avenue.