Police received a report that at around 2.50pm on Tuesday 1 May a man was assaulted on Halstead Road, Cosham.
This incident was reported by a witness and at this time the victim of the assault has not made contact with the police.
The offenders are believed to have been in a black BMW with heavily tinted rear windows which is likely to have contained up to four people.
Detective Sergeant Marcus Mills, said: “I am appealing for anyone with any information about this incident to come forward and speak to us. Were you in the area at the time? Did you see what happened or did you see a car matching the description in the area? I would urge anyone with information to make contact with us as soon as possible.”
If you have any information relating to this case, please call 101 quoting reference ‘44180160912’, or contact Crimestoppers anonymously.