A bomb disposal unit was seen on a residential street in Cardiff today (Friday).
The unit was in Clos Y Carlwm in Thornhill.
Residents said they had spoken to officers at the scene who said they would be updated in due course.
Others commented that the police would be there until Saturday afternoon.
However, one resident said they believed a man had been arrested by armed police in the morning and forensics officers and bomb disposal units were at the scene for the remainder of the day.
South Wales Police declined to comment tonight.
