Thames Valley Police is appealing for witnesses following an attempted robbery in Milton Keynes.
At around 2pm on Saturday (15/5), the victim, a man in his thirties, was walking through the underpass under Watling Street by Crownhill Roundabout towards the crematorium when he was approached by three men.
The victim was punched in the back of the head by one of the offenders who was wearing a knuckleduster. This knocked him to the ground.
The victim got up and was then threatened with a knife. He grabbed the knife, pushing it away from him and the offenders ran away.
The victim sustained a cut to his finger and a head injury for which he received hospital treatment. He has since been discharged.
The offenders are described as two black men, possibly Somalian, and a white man.
Investigating officer, Detective Constable Lisa McKinley, based at Milton Keynes police station, said: "I am appealing for anyone who may have witnessed this incident to please come forward.
"It happened in the middle of the day, near the play park, where I believe there is a good chance that people may have witnessed this.
"Anyone with information can contact police by calling 101 or making a report online, quoting reference 43210209425.
"Alternatively, if you wish to remain anonymous, you can contact the independent charity Crimestoppers on 0800 555 111 or via their website."