ACT Fire & Rescue has extinguished a small electrical fire on level six, in the roof of building "R1", Russell Offices, Russell Drive, Russell.
Approximately 800 people have been evacuated as a precaution.
Three fire pumpers on scene, the specialist Hazardous Materials Unit, the Breathing Apparatus Van, The Bronto Skylift Hydraulic Platform and a command officer.
Crews are currently conducting air monitoring and ventilation operations.
Update to follow.