A girl was hit over the head and knocked unconscious after being set upon by a gang of teenagers.
Detectives investigating the incident in St Albans after the victim remembered vital details about her attackers.
The incident happened between 5.30pm and 6.30pm on Sunday, June 5 when the victim was walking along the B5378 Shenley Lane, between St Albans and London Colney.
She was approached by four people before being hit on the head and falling unconscious.
When she came round, she had no recollection of what had happened to her but was left with pain to her head and bruising to her arms. Nothing was stolen.
Initially the victim was unable to give a description of the group, but has now recalled some details.
The group of four are now believed to have been one male and three females aged in their mid teens.
The male was wearing a black Nike tracksuit.
Female one has blonde hair, was wearing a white vest top and pink jogging bottoms and a lot of make-up.
Female two has red hair and was wearing black jeans and a pink vest top.
Female three has brown hair and was wearing a red vest top and white jeans.
Detective Constable Steve Cook said: “We are continuing with our investigation into this nasty and seemingly unprovoked incident which left the victim shaken and injured.
“I hope that people will recognise the description of the offenders and won’t hesitate to contact police so we can deal with them.
“I understand this incident may cause some concern in the community but I would like to reassure people we are doing all we can to establish what happened and why.
“The incident occurred near a busy stretch of road in broad daylight so it is likely there would have been a number of motorists around at the time.
“I am appealing for anyone who saw what happened or who saw anyone acting suspiciously in the area around the times stated to please get in touch.”
Anyone with information is asked to contact police on the non-emergency number 101, quoting crime reference F3/16/909.
Alternatively, call Crimestoppers anonymously on 0800 555 111 or use their Anonymous Online Form at www.crimestoppers-uk.org
No personal details are taken, information cannot be traced or recorded and you will never need to go to court.