BOKSBURG - Residents from the Jerusalem informal settlement in Boksburg are being temporarily evacuated after a truck carrying chemicals was burnt down nearby.
Its four-man crew was assaulted by a mob on Tuesday morning.
Three of the workers are being treated in hospital while the driver escaped the attack with minor injuries.
The truck was one of two set alight by a mob earlier.
It was carrying lubricant chemicals, including oil and acid.
The other truck, whose driver fled before it was completely destroyed, was carrying refrigerator tools.
It is suspected the attack is related to an ongoing strike by truck drivers.
Workers are demanding a salary increase of 12 percent for the next two years; however, employers are offering them around 8 percent.
Spokesperson for the Ekurhuleni Emergency Management Services, William Ntladi, said officials had already contained the spill and prevented the chemicals from leaking down man holes.
He said residents will be evacuated temporarily, until authorities can determine whether the acid spill will harm inhabitants.
In the Johannebsurg city centre, the truck drivers march is underway.
A few thousand marchers belonging to South African Transport and Allied Workers Union (Satawu) have are on their way to the bargaining council.