UPDATE: A 20-year-old man from New South Wales was taken into police custody around 4.00pm.

The centre of Civic was closed down and buildings evacuated around lunchtime today after a false bomb threat was made.

At 11.45am, a strangely behaving man left a suspicious package at the Civic Library and made comments about bombs, Detective Inspector Matt Reynolds, ACT Policing, said.

ACT Fire and Rescue and the police were called to the scene. They evacuated the library, Canberra Theatre, and surrounding buildings as a precaution; shut off London Circuit to vehicle traffic between Northbourne Avenue and Akuna Street; and asked pedestrians to avoid the area.

The item turned out to be harmless: a jacket wrapped around other clothing.

The suspect is known to police, Inspector Reynolds said. Police have CCTV footage of the man, and a description of his clothing.

The man will likely be charged with public mischief and causing public alarm, Inspector Reynolds said – offences that can incur penalties of up to 12 months imprisonment and a $5,500 fine, or imprisonment for 10 years.

Once they locate the suspect, police will consider further charges. Inspector Reynolds said it was important to understand the man’s motivation; it was possible the suspect might have a mental health issue.

Inspector Reynolds said it was frustrating that the incident wasted police, Fire and Rescue, paramedics, and ACT Roads resources, and disrupted businesses and venues in Civic Square.

However, he was happy that the public had approached the police and Fire and Rescue.

“ACT Police take all bomb threats seriously; we would ask people to contact police in the event of a bomb threat, and provide as much detail to us as you can.”

The nearby ACT Legislative Assembly was not evacuated; the police bomb response team said the building was distant enough from the scene until it could be assessed whether the package was a bomb. The public entrance was closed to visitors, while people inside were advised not to leave.