Two men got out of a car and assaulted a father and son who were also in a car, stopped at traffic lights on the Northway.
The incident happened on Friday, January 31, though police have only just released details to the press.
At around 8.50pm, the car in which the father and son were travelling was attacked by two men whilst stopped at traffic lights at the Carn junction.
When they got out of the car they were both assaulted by two men who had got out of a dark coloured Ford Focus which had also stopped at the lights.
The man and his son were treated at a nearby hospital for cuts and bruising.
Enquiries are ongoing and police have asked anyone who witnessed the assault to contact them on 0845 600 8000.