Two men have been released from hospital and another is in a stable condition after a brawl.
Braintree High Street was cordoned off for several hours on Sunday, with one section remaining shut until the evening, as forensic teams carried out investigations.
Police believe a disturbance started in Bar Sport before spilling out into the road.
Three men from Braintree had head and facial injuries after being assaulted.
One, a 26-year-old, suffered serious head injuries and is currently in a stable condition at Broomfield Hospital, Chelmsford, but improving.
An Essex Police spokesman said he had been punched and kicked outside Bar Sport.
A second man was taken to hospital with head injuries, the third made his own way to hospital. Both have returned home.
It is not clear if they were assaulted inside or outside the bar.
A spokesman for Bar Sport said: “There is a police investigation and we do not wish to make any comment.”
No arrests have been made.
Detectives would like to speak to anyone else who witnessed the incident at Bar Sport, either in the bar or outside.
Call Braintree CID on 101 or ring Crimestoppers anonymously on 0800 555 111.
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