Police have named a man who was murdered in Solihull on Saturday 30 November as Jack Donoghue.
Police were called to Poplar Road in Solihull at 3am after reports of a stabbing. The 21-year-old was taken to hospital but he died a short time later.
His family have paid tribute to a "loving son" and released a statement saying they are devastated.
Inspector Jim Mahon from West Midlands Police said, “Investigations are in the early stages and we are still trying to piece together what happened and the motive behind this attack.
“What we do know so far, is that five men were involved, none of whom were known to Mr Donoghue, and we want to appeal directly to any of those men to do the right thing and hand themselves in.
“We believe they will have confided with family and friends and urge anyone with information to help us with our enquiry.
"Jack’s family are understandably distraught at his loss and our thoughts remain with them."
“Finally, we want to thank everybody who has contacted us so far, the information provided will be invaluable to our investigation, and we continue to ask for anyone who hasn’t yet got in touch to contact us.”
The force says forensic investigations are continuing and CCTV is being extensively reviewed.