People going to a service at nearby Llandaff Cathedral were told they may have to change travel plans
Police are investigating the murder of a 23-year-old man found injured at an address in Cardiff on Christmas Eve.
Armed police were sent to the Llandaff area at about 11:30 GMT, and officers closed roads and a car park.
South Wales Police announced late on Christmas Eve that another man, also 23, was arrested on suspicion of murder.
Police said it was viewed as an isolated incident and nobody else is being sought.
Formal identification of the man who died has not yet taken place.
But police said his next of kin have been informed and are being supported by specialist officers.
The car park near High Street, Llandaff, was closed while police investigated
Police had said earlier that armed officers were deployed as a precaution to the incident on Chapel Street.
People going to a service in Llandaff Cathedral during the day were advised that their travel plans could be affected by the police investigation.
The cathedral posted on Facebook: “To all those attending our service of nine lessons and carols this afternoon the Llandaff High Street car park is closed due to an ongoing police incident.
“Please factor this into your travel and parking plans.
“Our thoughts and prayers are with those involved.”
