A man from St Leonards needed stitches after being struck over the head during a fight in Bexhill.
The 56-year-old victim was injured during an altercation with another man and woman in Sackville Road just after midnight on July 31.
The man was struck over the head with an object and suffered a cut to the head that needed stitches.
PC Sally Waldron said: “This was a noisy confrontation so there may be a number of people who saw or heard what happened but who have not yet come forward.
“I would urge anyone with any information to speak to us.”
A 38-year-old woman and a 32-year-old man, both from Bexhill, and a 56-year-old man from St Leonards have been arrested on suspicion of affray. All three were questioned before being released on bail until 8 September.
Anyone with information should call 101 quoting serial 14 of 31/07, email 101@sussex.pnn.police.uk