Pub staff were attacked by a group of men and left with bites, bruises and cuts while windows were smashed in a "dramatic" and "nasty" attack.
The victims were working at Jacobs Post in Church Road, Burgess Hill, when they were assaulted between midnight and 12.30am on Saturday 19 July after they asked a group of men to leave.
They suffered cuts, serious bruising and bite injuries in the attack and the pub's windows were also smashed.
A 45-year-old man and an 18-year-old man from Burgess Hill, an 18-year-old man from Haywards Heath and an 18-year-old man of no fixed address were arrested on suspicion of affray and criminal damage.
All four were questioned before being bailed until Saturday 6 September.
PC Samantha May said: "Although we have arrested a number of people, we still need to speak to people who saw what happened.
"The pub suffered a considerable amount of damage and the victims suffered some nasty injuries in the incident and we need to find as many witnesses as possible.
"This happened several weeks ago but was so dramatic that anyone who saw what happened is likely to remember it."
Anyone with information should email email@example.com quoting serial 32 of 19/07, call 101 or contact the independent charity Crimestoppers anonymously on 0800 555111.