A man was smashed around the head with a brick as he walked home from a friend's house in Oswaldtwistle.
The 25-year-old suffered a broken cheek after a thug struck him above his right eye just after he'd passed the Hare and Hounds pub.
Detectives said a group of youths hurled abuse at him as the victim tried to cut along a path towards Stanhill.
The victim said something back and headed towards a path between the community centre and Brittania Car Sales.
PC Mick Dewhurst said as he was about to enter the path he was hit around the head with the brick.
PC Dewhurst said the offence took place between 10pm and midnight on Sunday, June 3 which was the Jubilee Bank Holiday weekend.
He added: "I would appeal to anybody in the area of the Hare and Hounds pub around these times on the night or anybody that witnessed the attack near to the community centre to contact police.
"I’m particularly keen to speak with anybody that saw a group of youths on the pathway opposite the Hare and Hounds to come forward, especially if anybody thinks they may know them."
The offender who ran away is described as a male in his late teens, who had a skinny build and was wearing a black hooded anorak with the hood up.
The victim is a white male with short cropped blonde hair, stocky build and was wearing a yellow top, dark tracksuit bottoms, dark coloured baseball cap and blue trainers.
Anyone with any information should call PC 1159 Mick Dewhurst at Lancashire Police on 101. People with information can also contact the independent charity Crimestoppers anonymously on 0800 555 111 or on-line at www.crimestoppers-uk.org