A couple were threatened at knifepoint by three youths as they walked along a footpath in Wellingborough.
The incident took place on at some point between 7.30pm and 8pm on Friday, January 15, in Waterworks Lane, between Naseby Close and Westminster Road.
The couple were walking along the footpath, which backs on to Redwell Primary School and Redwell Leisure Centre, when they were approached by three young adults.
They threatened them and demanded items be handed over to them, but the victims had nothing to give them so the offenders fled.
It is believed one of the offenders was carrying a knife and another had an iron bar.
The victims suffered no injuries but were left severely shaken by what had happened.
One of the offenders was white, while the other two were black.
Police are appealing for witnesses to come forward.
Anyone with information should contact police on 101 or Crimestoppers anonymously on 0800 555111.