A 29-year-old woman was assaulted after becoming separated from her friends during a night out.
The victim left French's in Robertson Street, Hastings at about 11pm on May 16 and suffered a swollen lip and bruising to her arms and legs at some stage over the next few hours.
She also lost her tan brown faux leather handbag from her shoulder.
Sussex Police PC Amber Russell said: "At this stage we don't know what has happened to the victim so we need to speak to anyone that saw her late on 16 May or early on 17 May.
"The victim is about 5ft 4in and was wearing an orange top and blue jeans that night.
"If you recognise the description or saw a woman being hurt that night please contact us."
Anyone with information should call 101 quoting serial 399 of 17/5, email firstname.lastname@example.org or call the independent charity Crimestoppers anonymously on 0800 555111.