Posters went up around the city calling on people to “defend the Mercure” in the days before the protest. About 200 Avon and Somerset Police officers were in attendance.
Ch Insp Keith Smith said: “It is disappointing a group within the counter-protest has seemingly been intent on causing disorder.
“We’ve made several arrests and ordered a number of counter-protesters to leave central Bristol.
“I want to thank the officers who have worked tirelessly today to enable both protests to be kept separate, but it is totally unacceptable that officers have been assaulted.”
Mr Smith added that the force was awaiting on an update on the level of injury sustained by the officer in hospital.
A dispersal zone and enhanced powers will remain in place until 22:00 GMT.
