The man who died following an incident in Cardiff city centre early Sunday morning has been named as 21-year-old Asim Khan.
Mr Khan, who is from Grangetown was treated by emergency services at the scene and then taken to the University Hospital of Wales, Cardiff, where he died from his injuries.
His family are being supported by family liaison officers.
A 27-year-old local man has been arrested in connection with the incident and is currently in custody at Cardiff Bay Police Station.
They would like to speak to anybody who may have witnessed the incident, or who may have seen a suspect running away from the scene.
Detective Superintendent Richard Jones, from South Wales Police Major Crime Investigation Team, said: “A young man has tragically lost his life early this morning and we are doing all we can to bring those responsible for the murder of Asim Khan to justice.
“CCTV shows a disturbance which starts in the street near McDonalds and moves towards the Oxfam store where Mr Khan sadly collapsed having sustained a wound as a result of being stabbed.
“Significant police enquiries are continuing in the area and we thank the local community, including businesses and visitors, for its understanding while a number of cordons remain in place.”
Witnesses have described a suspect making-off initially in the direction of Wood Street, and then towards Penarth Road at the rear of Cardiff Central Railway station.
Anyone who may have seen the incident, the suspect or has any other information is urged to please contact South Wales Police.
Information and digital footage can be submitted online via a public portal https://mipp.police.uk/operation/62SWP19A91-PO1