Protesters set alight a minibus belonging to a private company in Phola near Ogies in Mpumalanga on Tuesday, police said.
Lt-Col Leonard Hlathi said the protesters were on the streets and the situation was “very tense”.
“The protest is not about service delivery, but employment at local coal mines.”
Schools and health facilities in the community were closed for the second day.
“Everything is at a standstill.”
Hlathi said he had heard there would be talks between the authorities and protesters on Tuesday.
Thirty-six people had been arrested for public violence. Thirty of them were expected to appear in court on Tuesday.