Thames Valley Police is appealing for witnesses to an attempted robbery in Milton Keynes.
The incident happened in Adelphi Street, Campbell Park at around 9.30pm yesterday.
The victim, a 25-year-old man, was walking back to his car when he heard someone behind him. He then felt a punch to his back and fell to the floor.
While he was on the floor, one of the offenders stood on his right hand while another tried to remove his rucksack.
He was also kicked in the ribs several times while one of the offenders asked him for his wallet.
A car then turned down the road and the offenders ran off.
Det Con Sam Reynolds, from Milton Keynes CID, said: “The victim saw three offenders, all wearing black clothing, run off in the direction of Campbell Park across the fields.
“We do not have any descriptions of the offenders as the victim was face down on the ground. However, one of the offenders was wearing classic wheat Timberland boots.
“Nothing was stolen in the incident, but the victim suffered swelling to his cheekbone, a cut lip and soreness to his chest and ribs.
“I’m keen to speak to anyone who has any information about this incident or who knows who may be responsible.”
Anyone with any information should contact Det Con Reynolds via the 24-hour Police Enquiry Centre on 101.
Alternatively, if you do not want to speak to police, or leave your name, please contact the Crimestoppers charity on 0800 555 111.