Several people are believed to have been injured in a chemical explosion at a company in Otto Volek Road in New Germany, Pinetown, on Tuesday.
Advanced life support paramedic Garrith Jamieson said there was a second explosion afterwards.
He said reports indicated several people were injured.
He appealed to people to give way to emergency vehicles and avoid the area.
On Friday, an explosion took place at the Engen oil refinery in Wentworth, Durban south.
One person was injured and six others were treated for smoke inhalation.
