Detectives investigating an attack in which three men were stabbed on a street in Sheffield city centre have released CCTV images of men they want to trace.
They believe the men could hold vital information about the incident on Carver Street on September 30, last year, in which three men, aged 19, 20 and 25, were stabbed at around 4.30am.
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One hour after the incident, violence flared on neighbouring Division Street and three other men men - aged 20, 22 and 30 - were also stabbed.
Two men have been charged over the incidents.
Anyone with information should call South Yorkshire Police on 101 quoting incident number 222 of September 30.