Waterkloof Airbase in Tshwane caught alight Sunday amid suggestions that fuel tanks were the source of the blaze that could be seen from a distance.
Late Sunday, a spokesperson at the airbase said the fire was now under control and there was no structural damage.
He could not say what the cause of the fire was. But he said the area was a secure area and no one could go there undetected. All areas are monitored 24 hours.
There were no injuries.
As many as seven fire trucks attended to the fire, said the spokesperson.
The fire chief was expected to continue inspecting the area and determining the cause of the fire on Monday.