A man and a woman were robbed while walking through Furzton on Thursday last week.
At around midnight, they were walking along a redway next to Bickleigh Crescent when two men jumped out from a gap in the bushes.
One of the men demanded both the man and the woman’s phones, but when they refused, he punched the male victim to the floor.
He then straddled the man and continued to punch him before taking out a knife and threatening him.
The second offender did not talk during the incident and stopped the woman from helping the man.
Both offenders then ran off in the direction of Redhuish Close.
The male victim suffered concussion, swelling and bruising to his face and had to go to Milton Keynes Hospital. He has since been discharged.
The man’s wallet was stolen in the incident which contained a driving licence, a cash card and quantity of cash.
The first offender is described as white, with a pale complexion. He is 6ft 2ins, has short black hair which was flattened, a black beard and moustache. At the time he was wearing black tracksuit trousers and a plain grey T-shirt.
The second man is also white and had a tanned complexion. He is of muscular build, and had a bald head. At the time he was wearing a grey v-neck vest top, white shorts and off-white espadrilles.
Det Con Wendy Cissell, from Milton Keynes Priority Crime Team, said: “I would like to speak to anyone who saw what happened or anyone who saw anyone acting suspiciously in the area at around the time of the robbery.
“Officers are working to identify and locate the offenders and I would encourage anyone with any information which could assist with enquires to speak to police.”
The victims had been walking in Twitchen Lane then walked through some trees before turning right on the redway shortly before the incident.
Anyone with any information should contact Det Con Cissell on 101 or Crimestoppers anonymously on 0800 555 111.