A teenage girl was assaulted twice in Hastings on Saturday evening (October 14) while watching the bonfire celebrations.
The 16-year-old and her friends, who she was with, were verbally abused by a predominantly female group close to the miniature railway in Rock-a-Nore Road around 9.50pm, police said.
One of the girls in the abusing group punched the girl in the face.
They walked away towards the crazy golf course, but were followed and the girl was attacked again, causing injuries to her face and knee.
She was treated by a St John Ambulance unit.
Sussex Police said the main suspect is described as white, around 16, 5ft 8ins tall, of slim build with very long brown hair and brown eyes.
She was wearing a crop top, jeans and a dark, possibly black, puffa style jacket.
Anyone who witnessed the assaults or has any information about the group or the girl who carried out the assault is asked to report online at sussex.police.uk/appealresponse or call 101, quoting serial 72 of 15/10.