Four people have been arrested on suspicion of murder after a man was stabbed in Milton Keynes.
Police were called to an address in Carradine Crescent, in Oxley Park, just after 3.30pm on Tuesday to reports of a stabbing.
Thames Valley Police said a man in his early 20s later died at Milton Keynes University Hospital.
A murder investigation was launched and four people have been arrested on suspicion of murder and remain in police custody, the force added.
Senior investigating officer Detective Inspector Dejan Avramovich said police believe the victim and attackers were known to each other and appealed for witnesses who may have seen an altercation in the area to come forward.
Det Insp Avramovich added: “This is a fast-moving murder investigation, and we currently have four people in custody in connection with this incident.
“The victim’s next of kin have been made aware and are being supported by specially trained officers at this time.
“I appreciate the concern that this incident will cause in the local community, but I would like to reassure members of the public that we have made arrests and are investigating the circumstances of this incident thoroughly.
“We believe the victim and the offenders were known to one another, and do not believe there to be a wider threat to the local community.”
Witnesses should call the police on 101 quoting URN 727 (31/12) or Crimestoppers anonymously on 0800 555 111.