A 64-year-old man have been arrested following a explosion at the office of the Department of Health in Thabo Sehume Street, police said.

Department of health spokesperson, Joe Maila said it is believed a petrol bomb was thrown at the entrance of the building.  

“The fire was restricted to the reception area, but everyone was evacuated to be safety,” Maila said.

According to Lieutenant Colonel Lungelo Dlamini  the 64-year-old man was detained on the scene and handed over to police.

“Police are investigating the matter,” Lungelo said.

According to spokesperson Johan Pieterse people in the building had to evacuated as the smoke was entering the premises.

“We managed to extinguish the fire,” he said.

According to Frikkie Gous, spokesman for Lifemed ambulance services no one was injured.

Spokesperson for the Tshwane Emergency Services Johan Pieterse said they managed to extinguish the fire.

“Police are investigating what caused the fire,” he said.

Motorists are urged to use alternative routes as police have closed the streets surrounding the department.