A 28-year-old man was found with a wound to the head and was treated at hospital.
Detectives are investigating a mass brawl at a bar in Leeds at the weekend.
Officers were called to The Arc in Headingley, shortly after 12.30am in the early hours of Saturday 17th February.
About 20 men had been fighting with each other and glasses and chairs were used as weapons. A 28-year-old man was found with a wound to the head and was treated at hospital.
A 21-year-old man was later arrested on suspicion of violent disorder and has been released under investigation.
Detective Inspector James Entwistle said: “The situation appears to have started with a confrontation between two people that has then quickly turned in to 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.
“We 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.”