Police investigating the death of a 21-year-old man in Cardiff city centre believe he was stabbed.
A large area of St Mary Street has been cordoned off after police were called to reports of an assault at 4.50am on Sunday.
Emergency services performed CPR at the scene before the man was taken by ambulance to the University Hospital of Wales in Cardiff where he died.
Police launched a murder investigation and have now confirmed that the man who died was 21-years-old and from the Grangetown area of the city.
Police believe the man was stabbed.
Detective Superintendent Richard Jones, from South Wales Police's major crime investigation team, said: “CCTV shows a disturbance which starts in the street near McDonald's and moves towards the Oxfam store, where the victim has collapsed having sustained a wound as a result of being stabbed."
Police said formal identification has not yet taken place, but that the man's family have been informed and are being supported by specialist officers.
Detective Superintendent Jones added: "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.”
Two areas of the city centre have been cordoned off by police.
There is police tape around one area next to Royal Arcade on St Mary Street and another area next to the Wetherspoon Prince of Wales pub.
The first site stretches from the entrance to Morgan Arcade, passing the Oxfam shop, Pieminister, The Grazing Shed and We Love Italy to Royal Arcade.
Staff from The Grazing Shed wrote on Twitter: "Our St Mary Street store is currently closed due to an incident on St Mary Street. We apologise for the inconvenience and will keep you posted with when we are able to open."
The second site surrounded by police tape is nearby and smaller, next to the Prince of Wales pub near Cardiff Central railway station.
A police spokeswoman said: "A number of officers continue to be in the area and a number of cordons remain in place while investigations continue."
Vicky Thomas, 36, from Riverside, said: “A couple of my friends were sleeping on the street last night.
"They saw it. They saw the man fall to the floor. They said it happened so quickly. There was blood on the street."
She added: "I’ve seen the forensics team putting things in bags. It’s getting dangerous on the streets.”
Jo Stevens, MP for Cardiff Central, described the incident as "dreadful" and encouraged anyone with information to contact the police.
Anyone with information is asked to call police on 101 or ring Crimestoppers anonymously on 0800 555 111 with reference 1900265784.
