The violence raged as the Constitutional Court was reviewing a landmark decision to jail Zuma for contempt of court
South Africa's army said on Monday it was deploying troops to two provinces, including its economic hub of Johannesburg, to help crush mob violence and looting as unrest sparked by the jailing of ex-president Jacob Zuma entered its fourth day.
"The South African National Defence Force (SANDF) has commenced with pre-deployment processes and procedures in line with a request for assistance," the military said in a statement.
Personnel will "assist law enforcement agencies deployed in Gauteng and KwaZulu-Natal provinces respectively to quell the unrest that has gripped both Provinces in the last few days," it said.
The violence raged as the Constitutional Court was reviewing a landmark decision to jail Zuma for contempt of court. An announcement is expected later.
The country's top court on June 29 slapped Zuma with a 15-month term for snubbing a probe into the corruption that stained his nine years in power.
Zuma began the sentence last Thursday but is seeking to have the ruling set aside.
"What we are saying is that this court made fundamentally rescindable errors," Zuma's lawyer Dali Mpofu argued in an on-line hearing before nine of the court's 11 judges.
Zuma had been treated unfairly and his "right to mitigation was limited," he said.
But one of the judges, Steven Majiedt, bluntly said Zuma had been convicted "because he disobeyed the order of this court."
Despite his reputation for graft and scandal, the 79-year-old former anti-apartheid fighter remains popular among many poor South Africans.
The epicentre of the unrest is Zuma's home region, the south-eastern province of KwaZulu-Natal.
Shortly before the military's announcement, troops were seen on the streets of its capital Pietermaritzburg and smoke billowed from the roof of a large shopping mall.
A retail shop in Durban was looted on Monday morning while in Eshowe, a town near Zuma's Nkandla home, police fired rubber bullets to disperse crowds after a supermarket was ransacked.
In Johannesburg, in Gauteng province, an AFP photographer saw a corpse at one site. The cause of the death was not immediately known. Sections of a major highway were closed. Police said more than 200 people had been arrested.
Some of the protests appear to have been triggered by Zuma's detention, but they are also associated with grinding unemployment and hardship inflicted by a toughening of anti-Covid measures.
President Cyril Ramaphosa on Sunday called on dissenters to protest peacefully.
"While there are those who may be hurt and angry at this moment, there can never be any justification for such violent, destructive and disruptive actions," he said.
Once dubbed the "Teflon president," Zuma started serving the jail term after handing himself in to authorities as a deadline for surrender loomed.
On Friday he lost a petition at the Pietermaritzburg High Court to have his case thrown out.
The court said it was not empowered to interfere with rulings set down by the Constitutional Court and that Zuma's claims about his health were not "supported by any evidence."
The anti-graft panel is probing the massive siphoning off of state assets that occurred during Zuma's 2009-2018 presidency.
He testified just once, in July 2019, but then swiftly withdrew his cooperation, saying he was offended at being treated as an "accused" and not as a witness.
Under the terms of his sentence, Zuma could be back home before Christmas as he would be eligible for parole in less than four months.
He separately faces 16 charges of fraud, graft and racketeering in an arms procurement scandal dating to 1999, when he was vice president.