Thirty-five people were injured in a blast at a pharmaceutical laboratory in South Africa's Mpumalanga province, police said Monday.
The blast caused a fire while badly damaging a part of the building, Xinhua reported.
The flames were eventually extinguished by the fire fighters and the injured rushed to hospital.
Rescuers were trying to find any possibly trapped person in the debris of the ruined building, police said.
Though a probe has been ordered to ascertain what caused the blast at the laboratory, some people said it could be an act of arson.