A major fire that left a historic Bristol building “extensively damaged” is being investigated by police.
Crews were called to the Guildhall in Small Street at 01:40 GMT and remain at the scene damping down.
Det Insp Andrew Branch of Avon and Somerset Police said officers were “treating the incident as suspicious at this time”.
Baldwin Street and Broad Street remain closed to vehicles but Small Street is open again, police said.
Buildings close to the fire were evacuated, including a number of students from their accommodation.
The fire service said the “extensive spread of fire” and concerns about structural stability forced crews to retreat from inside the historic building and douse the flames from outside.
The Guildhall was empty when fire broke out as it was about to be converted into a hotel.
Steve Quinton, area manager for Avon Fire and Rescue, said: “Where the fire was in the roof space that has now fallen into the building and several of the floors have gone through to the basement so we will continue damping down for a number of hours still.”
A structural engineer, Bristol City Council and the building owners have been to the site and an assessment will be made of how safe the building is.
The Guildhall is a Grade II* listed building.