Officers were called to the Arc bar, in Ash Road, Headingley, West Yorkshire, shortly after 12.30am on Saturday 17 February.
About 20 men had been fighting with each other and glasses and chairs were used as weapons, police said, with the suspects later running from the scene.
Shocking for staff
Detective Inspector James Entwistle, of Leeds District CID, said there had been "very little" that the bar's security could have done.
He explained: “The situation appears to have started with a confrontation between two people that has then quickly turned into a mass brawl.
“These were some very ugly scenes where people were punched, kicked and stamped on and glasses and chairs were thrown.
“The video shows how there was very little that the bar’s security could do to control the situation and it was clearly a shocking thing for staff and other people in the bar to witness."
Very clear CCTV
Entwistle said the police are treating this as an incident of violent disorder and are carrying out enquiries to identify those involved.
"We do have very clear CCTV footage that captures the whole incident and are working through that in detail to identify the main suspects.
“We would like to hear from anyone who knows the identity of any of those shown fighting in the clip we have released or who recognises themselves as a witness.”
Police said a 28-year-old man was found with a wound to the head and was treated at hospital, and that a 21-year-old man was later arrested on suspicion of violent disorder and has been released while investigations continue.
The Morning Advertiser has contacted the bar's owners, Arc Inspirations, but did not receive a response by the time of publishing.
Anyone who has information is asked to contact Leeds District CID via 101 quoting Operation Bartergill, or to call the independent charity Crimestoppers anonymously on 0800 555 111.