Emergency services have contained a fire in an Auckland CBD building.

The blaze broke out in the ground floor of the 15-storey Ballantyne House, on Customs Street East, near the Britomart precinct.

Around 30 firefighters were at the scene, having been alerted to the blaze at 3.30pm this afternoon.

A workman in the building suffered smoke inhalation, and was helped by both the fire service and St John Ambulance staff.

Police were helping manage traffic in the busy city streets surrounding the building.

Fire investigators will examine the scene.

Meanwhile, in Christchurch, two separate fires are being battled by fire crews.