Armed police surrounded a building in Cardiff Bay.

Pictures show police around the building at 3 Assembly Square.

One witness said they could see armed officers inside and outside the building and said it "looked like a siege".

The witness said police officers were in negotiations with a person in the reception area of the building.

Ambulances were also at the scene.

At 1.30pm, South Wales Police issued a statement.

It said: "At approximately 8.30am, officers were called to 3 Assembly Square, Cardiff Bay, following reports that a man was threatening to harm himself.

"The foyer and the area immediately around the building was cordoned off while specially trained negotiators were deployed to the scene.

"Firearms officers and the Welsh Ambulance Service Hazardous Area Response Team were also deployed but as a precautionary measure.

"At 12.30pm the man was detained without incident and the public are thanked for their cooperation throughout."