We are releasing an image of a man who we hope the public can help us identify as we want to speak with him to establish if he has any information that could help our investigation.
The public are urged to report online as much as possible despite the restoration of service; while 999 calls are answered being by Avon and Somerset Police staff again.
Sound equipment has been seized and arrests made after a unlicensed music event was brought to a safe conclusion in Bristol.
Emergency 999 calls are being taken with the support of neighbouring forces, so please only call 999 for genuine emergencies.