Firefighters were originally called to an automatic fire alarm at the building however en-route it was confirmed that smoke could be smelt by the occupants.
Firefighters are investigating the levels within the building and trying to determine the source and location of the fire.
As a precaution for the safety of occupants, the building has been evacuated.
One lane of Alinga Street is currently closed near the bus interchange. Northbourne Avenue is not currently affected.