An attack in which a man was stabbed to death and three others were injured happened at a house party, police said.
Marcus Ramsay, 35, was attacked in what police said was a "large-scale disturbance" in Horninglow Road, in the Firth Park area of Sheffield, at 00:20 BST on Saturday
He was taken to hospital but died soon afterwards.
Three other injured men, all aged 24, were treated at hospital and have been discharged.
Temporary Det Ch Insp Mark Oughton said he wanted to speak to people who had been at the party, adding the "answers to this investigation lie within the local community".
"I am aware that there were large numbers of people congregated on Horninglow Road due to a house party and I believe that many of them will have seen the altercation that led to Mr Ramsay being fatally injured," he said.
- 8 August