A desperate mother was forced to throw her baby from a burning building in the South African city of Durban after looters set fire to shops on the ground floor.

The woman was seen dropping the child down to a crowd of bystanders with their arms outstretched as smoke billowed around her. The baby escaped unhurt and was later reunited with its mother, the BBC reported.

It was one of countless scenes that have left South Africans in shock after six days of looting and arson in Gauteng and KwaZulu Natal.

Seventy people have died and more than 1000 have been arrested in the violence that began after former president Jacob Zuma was jailed for refusing to testify in to a corruption enquiry last week.

Over stretched police have struggled to respond and in many towns and villages local civilians armed with guns, clubs and knives have taken to enforcing their own law and order.

Now essential supplies are beginning to run out and ordinary people and logistics experts alike are warning of a “humanitarian disaster”.

Late on Tuesday night (local time), Durban’s Sapref oil refinery, the country’s largest, said it was temporarily shutting down production because it could not guarantee the security of its staff.

Sapref accounts for about a third of South Africa’s fuel supply and experts warned that shortages were “inevitable” in coming days.

Meanwhile, disruption on the roads, the looting of warehouses and rampant violence in urban centres has interrupted deliveries of crops from farm to markets and the onward supply chain to retail outlets – raising fears of a catastrophic food shortages.

“We need the restoration of law and order as soon as possible, because we are going to have a massive humanitarian crisis,” said Christo van der Rheede, executive director of the largest farmers’ organisation, AgriSA.

Gavin Hudson, chief executive officer of sugar producer Tongaat Hulett Ltd, told Bloomberg: “Food is going to be a problem because shops haven’t been open for three days and many with bulk storage have been looted … We are going to face some food issues in KwaZulu-Natal very shortly.”

In Gauteng and Johannesburg, the momentum of the violence appeared to have slowed on Wednesday afternoon.

“All is finished here. There is nothing left. No shops. No food, no water. Nothing, nothing, nothing. All burned, or taken,” one resident of the Johannesburg township of Alexandra, one of South Africa’s most congested and pitifully poor, told the UK’s Daily Telegraph by phone.

In some affluent parts of the city, people were even eating in restaurants at pavement tables as if nothing had happened.

The shops, which were all closed from Monday, have reopened and there was some mass buying by residents seeking to stock up in case food supplies dry up.

Queues of about 20 people, socially distanced, could be seen outside five supermarkets visited by the Telegraph on Tuesday afternoon.

But the worst suffering has hit the poorest areas.

One of the saddest losses in ‘Alex’m, which lies just a mile from one of Johannesburg’s wealthiest neighbourhoods, was the township radio station, which was fully owned by residents. Its equipment was completely destroyed.

In Soweto, the giant township on the western outskirts of the Johannesburg, locals successfully defended the Maponya shopping mall from looters on Tuesday night, although two others were completely wrecked.

“They got the malls and the spazas (tiny, temporary wooden shops, mostly run by Somalis). So I told my mother, today: ‘Maybe I won’t come home again, maybe I will die, but we will save the mall,” said Nhlanhla Lux, a Soweto resident, said.

Bishop Paul Verryn, a widely respected peacemaker who lives in the township, praised the locals who came out to defend the mall but warned the worry was about a shortage of essential supplies.

“The people have saved Maponya Mall. It will survive. But Jabulani Mall, so close to where I live, is gone,” he told the Telegraph. “We don’t know how restocking will take place.”