Patrolling officers noticed a fight involving approximately 20 people taking place outside of the trouble spot shortly before midnight.
Officers stopped to assist and on attendance one of them, an officer in his 30s, was assaulted causing a serious injury to his face. He was taken to Queen Alexandra Hospital for treatment and has since been discharged.
The group dispersed and officers have arrested four people in connection with this incident.
A 23-year-old man from Portsmouth has been arrested on suspicion of affray, Section 18 wounding with intent and possession of a controlled drug of Class A.
An investigation is underway into the incident and the drug and violence-blighted venue and police would like to hear from anyone who was at the pub at the time or in the moments before the incident and saw what happened.
Detective Inspector Mark Alleman of Hampshire Constabulary’s Criminal Investigation Department said, “This was a particularly nasty altercation involving a large number of people in a public place, some of whom we’d still like to speak to.
“We believe there are still victims who may have been injured in the incident that are yet to come forward. If this is you, we’d like to hear from you.
“We also want to hear from anyone who saw what happened, either outside of the pub at the time or in the lead-up to the incident.”
Anyone with information is asked to call 101 quoting reference 44210519421. Alternatively, you can submit information via the following form: https://orlo.uk/dai5M