06/11/2013 09:07 EDT | Updated 06/12/2013 10:18 EDT

Calgary Bow Tower Evacuated By Police After Alleged Threats

Twitter, ChrisDDumont

CALGARY - Threats by an unknown man forced the evacuation of Calgary's tallest building.

Occupants of the Bow, a 58-storey office tower, were cleared floor by floor on Tuesday afternoon after a suspicious man was spotted in several different locations.

Calgary police say the man made unspecified threats inside the building and when security tried to deal with him he slipped away.

The threats are being described as bizarre comments and included references to terrorists.

The suspect was in a secure area of the building which required security card access.

Witnesses say the evacuation was orderly and calm even though access to the elevator was restricted, meaning many people had to walk down more than 50 flights of stairs.

Police remained on scene throughout Tuesday evening.

Tenants of the building include Cenovus Energy, EnCanada Corp., and Ledcor Construction.