A 15-year-old girl was bruised and had lumps of her hair pulled out in an alleged assault in Bridlington.
Humberside Police want to speak to a van driver who may have witnessed the alleged assault which involved a group of teenage girls in Jubilee Avenue.
The incident happened on Monday May 14 at around 3.30pm.
Anyone with any information or who witnessed anything is asked to call police on 101 and quote reference 16/53020/18.
A spokesman for the force said: "A 15-year-old was bruised and had lumps of hair pulled out."