Several people have been assaulted in the Redcatch Road area of South Bristol.
Three people have been hospitalised, but none of the injuries are believed to be life-threatening.
Avon and Somerset Police, who were called to the scene at 3:10pm today (25/02), arrested a man in his 30s on Redcatch Road - he remains in custody.
Officers say they are not treating the incident as terrorism-related.
Emergency services are at the scene and a full investigation is underway.
A37 Wells Road in Knowle is currently shut in both directions between the Redcatch Road and Broad Walk junctions as a result.
Drivers are being advised to avoid the area if they can, with travel disruption expected between Bristol and Pensford.