Police respond with everything from rubber bullets and live ammunition – nine people have been shot dead so far this year – to shrugs of the shoulders, reflecting the pressure on officers faced with a seemingly unending flow of black anger two decades after the end of apartheid.
In the last three months alone, police in the province of Gauteng have been called out to at least 569 "service delivery" protests, as they have become known. Of these, more than 120 have been violent.
With elections now scheduled for May 7, the demonstrations are starting to take on an increasingly political tone, suggesting they are likely to get worse in the next two months.
On Friday, when rioters barricaded roads, pelted vehicles with stones and looted a Pakistani-owned store in Hebron, a township in rolling hills 30km northwest of Pretoria, the police response was too little and too late.
"There's nothing I can do," said warrant officer Solomon Swaratlhe, a veteran of more than 30 years in the SAPS who cannot remember such persistent lawlessness – not even in the dying days of white-minority rule in the early 1990s.
"This is worse than anything I have seen. I was phoning and phoning but the others didn't come. What can one police car do?" he said.
An R5 automatic rifle is tucked under his arm but Swaratlhe, mindful of persistent accusations of police brutality, is loathe to use it.
"I don't kill. I'm just here to protect," he said. "I haven't eaten since 5:30am this morning [Friday]. I'm so angry and tired. This is so bad. We don't want to kill them. We just disperse them, keep on dispersing them every day."
'A nation burns'
The protests often arise from single, unrelated incidents – a broken sewage plant, the murder of a child, a water outage or, in the case of Hebron, a dilapidated bridge near a school.
They also have little direct impact on Africa's biggest economy, taking place in forlorn communities far from the bright lights and factories of Johannesburg, Cape Town and Durban.
The protesters themselves are almost all out of work, victims of an economy struggling to recover from a 2009 recession and which, even in the boom years before the global financial crisis, still suffered unemployment above 20%.
However, the unrest is fueling concerns about wider social stability in a "Rainbow Nation" that has failed to live up to Nelson Mandela's dream of equality, freedom and prosperity for all.
Opposition political parties are seizing on the anger as evidence of the failings of the ANC, whose affirmative action policies have made limited progress in narrowing racial inequality, with the average white household still earning six times more than the average black one.
On Friday, The Star newspaper plastered a picture of a street littered with burning tyres across its front page under the headline "A Nation Burns". Editorials make comparisons to the chaos that prevailed in the dying days of apartheid.
The difference between now and two decades ago is that the ANC is the target of the fury, not its instigator, suggesting the party that has ruled since 1994 may take a hit on election day even though it is almost certain to maintain its majority.
"People are never going to vote for the ANC because they are so angry," said 26-year-old unemployed Jerry Tlou outside a looted store in Hebron.
Five years ago, he voted for the ANC but says he is so sick of the broken promises and corruption scandals that have marked President Jacob Zuma's first term that he is backing the opposition Democratic Alliance, even though it is still seen by many as a "white" party.
"The ANC makes all these promises but they can't deliver. No water, no electricity, they can't fix the roads. I am going to vote for the DA," he said.
Others in the crowd outside the shop were pinning their hopes on Julius Malema, a renegade ANC Youth League leader who was kicked out of the party in 2012 and now leads the militant, left-wing Economic Freedom Fighters (EFF).
Although investors blanche at Malema's rhetoric about nationalisation of mines, banks and farms, his words fall on fertile ground in places like Hebron.
Some analysts say the EFF could poll 5% or more nationally, votes that will come at the expense of the ANC and could push its support below the psychologically important 60% mark, causing big problems for Zuma.
"We need jobs. We need work," said 38-year-old David Menziwa. "We've got the qualifications but we're doing nothing. We're voting for Malema because he can help us." – Reuters