A 16-year-old was assaulted by a group of girls outside a fish and chip shop in Bognor Regis, according to Sussex Police.
Police are appealing for witnesses to the incident in Station Road between 9 and 9.20pm on Saturday evening (February 16).
A spokesman said: "The 16-year-old victim was attacked by a group of girls outside a fish and chip shop in Station Road.
"Passers-by intervened and the group walked off in the direction of Morrisons.
"Anyone who witnessed the assault is asked to report online at www.sussex.police.uk/contact/af/contact-us/ or call 101 quoting serial 1192 of 16/02."