Pretorai - The reception area of the health department's building in the Pretoria CBD was set alight on Wednesday afternoon, police said.
A 54-year-old man poured a flammable substance and set it alight, spokesman Lt-Col Lungelo Dlamini said.
He ran away, but security guards caught him.
“He was handed to police and a case of arson has been opened. The motive is still unknown at this stage,” he said.
The fire damaged the glass doors and ceiling of the reception area.
Tshwane emergency services spokesman Johan Pieterse said when firefighters arrived the fire had been contained.
“The occupants inside managed to extinguish the fire and we evacuated the building as a safety precaution,” said Pieterse.
The fire caused gridlock in the CBD as Thabo Sehume street had to be closed.
Metro Police spokesman Isaac Mahamba said officers were sent to help with traffic flow.
“Traffic has been seriously affected as we had to close the street during peak hour. We appeal to motorists, if possible, to avoid coming into the CBD,” said Mahamba.