Spokesman Eddie Gershon said staff at The Clifton had gone to help an injured man after two assaults involving a group of men near a taxi rank.
A group was caught on the pub’s CCTV attacking two men, one was able to shelter inside the pub then they attacked another, he said.
“Once the group dispersed, door staff at the pub went to assist him on the floor putting him in the recovery position.”
The scene, in Bull Ring, remains closed for investigations, as do a number of roads in the area, including Sedgley Road, Bilston Road and Vicar Street.
Police appealed for anyone with information to get in touch and they would be increasing neighbourhood patrols to reassure the local community.