A man apparently holding a black handgun was involved in an incident with another man in Long Buckby.
The altercation happened on Sunday, December 16, between 7.20pm and 7.40pm in Station Road.
A Northamptonshire Police spokesman said one man was in a white Transit van and had a claw hammer.
The other, who was walking along the street, was joined by a group of friends, one of whom had what looked to be a black handgun.
The man in the van is described as white, in his early 20s, skinny, about 6ft, with stubble.
He had black hair shaved on the side and curly on top and he was wearing a white, grey and black T-shirt.
The man thought to have had a gun is described as white, skinny, about 6ft, wearing a black hoody, baseball cap, and black tracksuit bottoms.
Witnesses or anyone with information should contact Northamptonshire Police on 101. Alternatively, they can call Crimestoppers anonymously on 0800 555 111.