A man has been taken into custody and is assisting police with inquiries following an incident near the ASIO headquarters on Wednesday afternoon.
Police said they responded to an incident at a building on Constitution Avenue in Campbell shortly after midday.
Access to Constitution Avenue between Anzac Parade and Russell Offices was blocked for a number of hours as police cordoned off the area.
Nearby businesses and some residents along Constitution Avenue were evacuated about 12.20pm as police patrolled the area near the ASIO buildings.
Onlookers were ordered away from the scene. One witness said a nearby resident was ordered off their balcony as a police operation was under way.
A person who was evacuated from a nearby business in the Campbell 5 precinct told The Canberra Times police did not give them a reason for why they had to evacuate.
Another was blocked when they tried to leave.
ACT Ambulance Service vehicles also attended the scene.
An ACT Policing spokesperson confirmed police had responded to an incident at a building on Constitution Avenue about 12.10pm on Wednesday.
Nearby buildings were evacuated as a precaution, the spokesperson said.
While the public was ordered to stay away from the area, police said members of the public were not at risk.
"There is no threat to the wider community," an ACT policing spokesperson said.
At 3pm, the spokesperson said the incident had been "finalised".
ASIO was asked about the incident but would not comment. Instead, the organisation directed inquiries to ACT Policing.
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