A Corby garage was robbed by a man who was holding what police believe was a silver handgun.
The incident took place at about 4.30pm on Friday (November 11) at the Esso garage in Oakley Road.
The offender approached the cashier, demanding cash and cigarettes while holding what appeared to be a silver handgun.
The shop assistant handed over the items and the offender made off.
The offender was a white man wearing a black balaclava, a black jacket with a white zip and white tick on the left chest area.
He wore black gloves, dark trousers, dark trainers and rode a black mountain bike.
The shop assistant was not injured in the incident but was left very shaken by what happened.
Officers investigating the incident would like to speak to anyone who may have witnessed it, or who may have seen a man matching the description of the offender in the area between 4.30pm and 4.45pm.
Witnesses or anyone with information about this incident can contact police on 101 or Crimestoppers anonymously on 0800 555111.