Police in South Bristol say a knife was recovered after they were called to reports of someone on roller skates 'attacking people'.
A person was tasered just after 3pm yesterday afternoon in the Wells Road area .
Three people were injured and we're told investigations continue.
Chief Inspector Nigel Colston, neighbourhood commander for South Bristol, said: "This kind of incident is extremely rare in Bristol and while we’re keeping an open mind about it, I’d like to reassure people we do not believe it to be terrorism.
"A full investigation is already underway and a team of detectives are working hard to establish exactly what happened.
"They have a significant number of witnesses to speak to and will be carrying out other enquiries, including house to house and CCTV enquiries in the coming days.
"Several members of the public bravely intervened in the incident and I’d like to praise their bravery and thank them for their assistance.
"South Bristol is a safe area and they demonstrated great courage and community spirit when faced with a very unusual incident.
"I’d also like to thank the two officers who detained a man who threatened to cause them harm.
"No one should be threated while at work and the way they dealt with the situation was a credit to themselves and to Avon and Somerset Police."
Officers were dispatched to the Wells Road area at 3.10pm after multiple calls about a man on roller skates 'attacking people'.
On arrival at the scene, two officers were threatened by a man with a knife. One of the officers deployed their taser in the process of detaining him.
The man, aged in his 30s, was taken to custody were he remains.
A knife was recovered from the scene.
Two men, one aged in their 20s and the other in their 50s, sustained stab wounds in the incident and are currently receiving treatment at Bristol Royal Infirmary. Their injuries are not life threatening.
A third man, also aged in his 20s, sustained a head wound. He was taken to the same hospital but has since been discharged.
Chief Inspector Colston added: "We expect the specialist crime scene investigators to soon finish examining the area and we’ll then be able to lift the road closures.
"I appreciate the closures have caused disruption and I’d like to thank the public for their patience while we carried out the necessary enquiries.
"Neighbourhood officers will be carrying out reassurance patrols during the next few days and anyone with any concerns is encouraged to speak to them."