A man has been arrested on suspicion of murder after allegedly stabbing another man to death.
Emergency services were called to a property in Bedford Street in central Gloucester at about 07:40 BST.
Three men were taken to hospital, Gloucestershire Police said, one of whom died at about 12:00.
The suspect, in his 30s, was arrested by armed police a little more than a mile away from the scene, in Chequers Road, at about 08:10. He was also taken to hospital for treatment.
He has since been discharged and transferred to police custody.
The man who died has not been formally identified, but investigators have said they believe they know who he is and his family have been informed.
The two other victims remain in hospital but their injuries are not thought to be life-threatening.