Meanwhile as deadly rioting continues, more than 2200 people have been arrested, said Khumbuzo Ntshaveni, a minister in the president's office, including a man alleged to be the instigator behind the wave of looting.

About 10,000 soldiers had been deployed on Thursday, she said, after the Defence Ministry prepared to mobilise an additional 25,000 soldiers to help quell the unrest amid fears of a rise in vigilantism.

About 100 acts of violence had been recorded on Wednesday but fewer than three dozen on Thursday, Ntshaveni said.

Chaos erupted across swathes of the country following the imprisonment of former president Jacob Zuma a week ago.

The protests devolved into unchecked looting, arson and violence.

Clean-up work began in many places on Thursday.

Initial estimates are that the damage runs to hundreds of millions of rand and affected about 20,000 jobs.

Television images of a looted hardware store in Pietermaritzburg showed the recovery of several bodies.

All available reservists would receive orders, the army said in a statement of its plans late on Wednesday, which would mark one of the largest military operations in 27 years of South African democracy.

The soldiers were to report to their units with all their equipment on Thursday.

Defence Minister Nosiviwe Mapisa-Nqakula informed parliament of the operation earlier in the day, South African broadcaster eNCA reported, but it has yet to be approved by President Cyril Ramaphosa.

About 5000 soldiers have already been deployed to help police keep the peace in hard-hit areas.

Police Minister Bheki Cele announced the discovery of tens of thousands of rounds of live ammunition in a suburb of Durban.

"Some people are preparing for the war out there," Cele said on Wednesday night.

"There are people that are arming themselves - whatever they are preparing for," he told reporters, calling it "a dangerous situation".

House searches had begun in Gauteng province around Johannesburg as part of the operation to end the violence.

"It's going to be a very tough time in many houses, in many homes around SA," Cele said.

The port city of Durban and the surrounding province of KwaZulu-Natal have been particularly affected by the mob violence, prompting civilian vigilante groups to take the law into their own hands to protect their homes and businesses.

In Durban, as well as the township of Alexandra near Johannesburg, long queues had formed on Thursday outside the few stores and petrol stations still open.

The protests have inflamed racial tensions, with at least four Somalis killed in apparently xenophobic attacks in recent days.

There were reports on Thursday of bloodshed in Phoenix, a suburb of Durban, after clashes erupted between Indian and black communities.

Zuma was sentenced to 15 months in prison, which he began serving last week.

He faces a commission of inquiry into various corruption charges during his time in office, from 2009 to 2018, but had failed to comply with a court summons.

Australian Associated Press