Vandals have caused 'substantial damage' by throwing red paint over walls and floors at student accommodation in the city centre.
Officer have released CCTV images of two men they want to trace following the incident at St Lawrence House, shortly before 7pm, on July 17.
Graffiti was also sprayed on walls during the incident.
Avon and Somerset Police has now launched an investigation and are appealing for witnesses to come forward.
A force spokeswoman said: "We’re releasing CCTV images of two men we’d like to speak to in connection with the incident.
"If you recognise them, or have any information that could help police with their investigation, please call 101 quoting reference 5220158436."
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