A man found with stab wounds at a flat in Birmingham died before he could be airlifted to hospital.
The Somali victim, who has not been formally identified, was found collapsed at Ladypool Road, Sparkbrook, just before 16:30 GMT.
The air ambulance was called, the force said, but the victim was pronounced dead before he could be taken on board.
Officers have appealed for anyone with information to come forward.
Det Insp Jim Mahon, said: “We understand there was a disturbance at the address which has resulted in a man losing his life.
“We’re in the process of speaking to several people who were present at the property and are following up numerous lines of inquiry.”