A 19-year-old woman was assaulted in Senwick Drive, Wellingbrough, at around noon on Wednesday, November 14.
The woman was walking along an alleyway between Senwick Drive and Senwick Road, when she was approached from behind by a man who assaulted her before making off.
The offender was a black man, around 5ft 10in tall, of thin build and in his late teens. He was wearing a dark blue hooded top.
The victim received minor injuries during the incident.
Officers would like to speak to anyone who may have witnessed this incident or have any information regarding it.
Witnesses to this incident, or anyone with information, should call Northamptonshire Police on 101 - alternatively, information can be given anonymously to Crimestoppers on 0800 555 111.