At around 3.30am on Sunday morning, a group of people were present when an altercation took place on Parliament Street, outside the bar.
Police are appealing for all of these people to come forward as they could have important information which could assist the police investigation.
They would particularly like to hear from two women who were stood outside the bar at the time and saw what happened, one of them is believed to have been hit by the suspect.
A man is also believed to have been hit a short time later by the same suspect in a nearby street.
PC Jim Martin of Harrogate police said: It’s important that anyone who was present during the incident comes forward to the police with information. CCTV shows a number of people in the area at the time and it’s vital that we speak to them.
If you wish to remain anonymous, you can pass information to Crimestoppers on 0800 555 111.
Please quote reference 12140041920 when passing on information about this incident.
A 21-year-old man has been arrested in connection with the incident and released on police bail.