A murder investigation has been launched following the death of a man in the city centre of Cardiff.

Officers were called to St Mary’s Street about 4.50am after reports of an assault, South Wales Police said.

The dead man has not been formally identified, although police said he is believed to be a 21-year-old from Grangetown in the city.

“Officers and the police helicopter continue to be in the area and a number of cordons remain in place while investigations continue,” police said.

Detective Superintendent Richard Jones, from the Major Crime Investigation Team, said: “A young man has tragically lost his life early this morning and we are doing all we can to identify the person responsible.

“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.

“Significant police inquiries 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 the suspect making off initially in the direction of Wood Street, and then towards Penarth Road at the rear of Cardiff Central railway station.

Anyone with information is asked to phone 101 and quote reference number 1900265784.