Detectives investigating a stabbing in Doncaster town centre have issued CCTV images of men they want to trace.
A 23-year-old man was stabbed in his back last October but the culprits have never been caught.
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He was walking along Bowers Fold after leaving a nightclub in Silver Street when he was attacked in the early hours of Sunday, October 1.
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A group of men approached the victim from behind and assaulted him, leaving him with a stab wound to his back, which needed hospital treatment.
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It is thought that the group of men had been involved in an altercation inside the nightclub before violence flared outside.
Detective Constable Della O’Horo said: "Our investigation has continued in earnest since this matter was reported to police and in early October we released an appeal for witnesses.
"As the victim was approached from behind in this violent attack he was only able to provide limited information. Any assault with the use of a weapon could prove fatal, which is why it’s vitally important we establish the circumstances surrounding this incident."
She added: "Extensive enquiries have been undertaken in a bid to identify those responsible, including seizing any items from both inside the nightclub and the scene of the assault for forensic opportunities and circulating the CCTV images we’re now sharing with the public across all officers and staff within South Yorkshire Police.
"We’ve worked closely with local businesses and spoken to several witnesses, but have been unable to identify anyone involved in this incident.
"We believe the individuals pictured hold important information about the sequence of events that evening and I’m appealing to those individuals directly to contact police. If anyone recognises those pictured, please call us."
Call South Yorkshire Police on 101 and quote incident number 185 of October 1.
Crimestoppers can also be contacted, anonymously, on 0800 555 111.