Officers are appealing for information and witnesses following an assault in Bovingdon last month.
The incident happened at Bovingdon market on Chesham Road at around midday on May 19.
Following a verbal altercation, a 41-year-old man was assaulted by three men.
One of the men is described as white, aged in his 40s, of an average build, around 5ft 10in tall and with short black hair. He was wearing a T-shirt, shorts, black boots, a hat and sunglasses.
The second man is described as white, in his early 20s, of a stocky build, with short light brown hair. He was shorter than the first man and was wearing grey jogging bottoms, black trainers and no top.
The third man is described as white, aged around 18, quite tanned and of a stocky build. He was shorter than the two other men and was wearing a light sandy coloured vest with sparkly gold writing and grey tracksuit bottoms.
The victim was taken to hospital and as a result of the assault, he suffered cuts to his head and hands and fractures to his ankle.
DC Jane Swift, who is investigating, said: “This was a vicious attack, during which the victim lost consciousness. Thankfully this was regained.
“The incident took place in a very busy location so I am confident that there are witnesses who can help us with the investigation.
“If you saw what happened or have any information please contact me on firstname.lastname@example.org or the non-emergency number 101, quoting crime reference D1/18/4159.”
You can also report information online at www.herts.police.uk/Report
Alternatively, you can contact the independent crime-fighting charity Crimestoppers anonymously on 0800 555 111 or visit www.crimestoppers-uk.org. No personal details are taken, information cannot be traced or recorded and you will never need to go to court.