Security forces in South Africa are struggling to contain spreading unrest, with dozens dead after violent scenes that President Cyril Ramaphosa admitted have “rarely [been] seen before in the history of our democracy”.

The immediate trigger for the violence was the jailing last week of Jacob Zuma, the former president, for contempt of court for his refusal to attend an inquiry into corruption during his nine-year tenure.

Zuma, who still has strong support within the ruling African National Congress and in his home state of KwaZulu-Natal, has denied all wrongdoing and says the charges are politically motivated.

South Africa’s domestic spy agency is investigating whether its own former agents had orchestrated violence in KwaZulu-Natal out of loyalty to Zuma, said Ayanda Dlodlo, the state security minister, at a briefing on Tuesday. A leading business family related to Zuma denied this week that it was behind the unrest. The province is the former president’s power base and has a long history of political violence.

While analysts suggest the violence may have initially been fanned by Zuma’s supporters, high youth unemployment and economic disruption from the pandemic have also fuelled the looting and unrest. Riots that began in KwaZulu Natal have since spread to other areas including Gauteng, the economic hub that includes Johannesburg.

Sihle Zikalala, premier of KwaZulu-Natal, said on Tuesday that 26 people were confirmed dead so far in the province. Queues formed outside the few supermarkets remaining open after looting in Durban, the province’s biggest city. The main N3 motorway from Durban to Johannesburg, a major economic artery for South Africa and the region, was also largely shut on Tuesday. David Makhura, Gauteng’s premier, said that 19 people had died in the province, including 10 in a stampede in Soweto.

Hundreds of looters also ransacked industrial warehouses on the outskirts of Durban, which is one of Africa’s busiest shipping ports. A chemical plant in the region was also set on fire.

Ramaphosa ordered the deployment on Monday of up to 2,500 soldiers to support police and said that South Africans were “anxious and afraid” about societal breakdown. “This is not who we are as South Africans. This is not us,” he said in a televised address on Monday.

But there was little sign on Tuesday of the promised military deployment on the streets, and the government is under heavy criticism in South Africa over a lethargic police response to the insecurity. “The situation was allowed to reach this point precisely because our law enforcement agencies failed to take control early on and do their jobs,” said John Steenhuisen, leader of the main opposition Democratic Alliance.

South Africa’s high joblessness and sharp post-apartheid economic divisions provide a tinderbox for violence, made worse by the pandemic pushing many even further below the poverty line. An already slow pace of vaccinations has ground to a halt as medical centres have been forced to shut their doors. Official unemployment was almost 33 per cent in the first three months of this year.

The rand slid by more than 1 per cent on Tuesday to 14.59 to the US dollar as traders bet that the unrest would undermine the country’s economic recovery. The currency, down 3 per cent so far this week, is at its weakest level since early April.

One South African television station broadcast live images of looters running away from a police van as officers looked on. “This moment has thrown into stark relief what we already knew: that the level of unemployment, poverty and inequality in our society is unsustainable,” said Ramaphosa. As he was speaking late on Monday, South African TV carried a split screen image of looters breaking into a blood bank.

Additional reporting by Tommy Stubbington in London