A man threatened the occupants of a car with a gun after blocking it at a junction in Geddington.
The incident took place in Stamford Road at about 9pm on Sunday (April 15).
A car was followed through Geddington by a silver vehicle, which then blocked in the other car at the junction of West Street and Stamford Road.
One of the men in the silver car produced a black revolver, pointed it towards the people in the other car and made threats.
The silver car then made off along Newton Road towards Newton.
The suspects are three white men and the car was possibly a Vauxhall Vectra.
Witnesses or anyone with information should call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.