Detectives are appealing for witnesses to an assault outside a Wakefield pub which left a man with a fractured jaw.
Officers today released CCTV footage of a group of people they would like to trace.
It is believed they may have witnessed the assault or seen the suspects involved.
The assault took place the early hours of New Year's Day outside a pub house in Sandal.
Police were called to Barnsley Road at around 1.30am after a man in his 30s was attacked and knocked him to the ground.
He was taken to hospital and treated for several injuries, including the fractured jaw.
Inspector Dan Tillett, of Wakefield Disctrict CID, said: "This is a serious offence in which the victim has been subjected to an assault which left him with serious injuries.
"I would appeal for anyone who witnessed the incident to please get in touch.
"If anyone recognises the people pictured in the CCTV images, could they please contact police as we believe they may have information on who has carried out this attack."
Anyone with information is asked to contact Detective Constable 4025 Chris O'Brien at Wakefield CID on 101, quoting crime reference 13170003298.
Information can also be passed anonymously to Crimestoppers on 0800 555 111.