Anti-immigration protest erupts in South Africa as demonstrators demand expulsion of foreign nationals (see video)

• South Africa has increased security nationwide ahead of anti-immigrant protests linked to an unofficial June 30 deadline set by groups demanding undocumented migrants leave the country.

• Police Minister Firoz Cachalia warned that "crime, intimidation, violence, destruction of property and any attempt to undermine public safety will not be tolerated."

• Thousands of migrants, mainly from Malawi and Zimbabwe, are awaiting repatriation after reporting evictions, job losses and threats amid rising xenophobic tensions.

• Authorities fear a repeat of past xenophobic violence, including the deadly 2008 riots, as security forces remain on high alert to prevent attacks and maintain order.

South Africa has stepped up security across the country as authorities brace for nationwide anti-immigrant protests linked to an unofficial June 30 deadline set by groups demanding undocumented migrants leave the country.

Thousands of police officers and other security personnel have been deployed in major cities and potential flashpoints, with the government warning that violence, intimidation and attacks on foreign nationals will not be tolerated.

The protests come after weeks of rising anti-immigrant tensions, with undocumented migrants, particularly those from other African countries, becoming the target of intimidation, evictions and threats.

Police Minister Firoz Cachalia said law enforcement agencies are prepared to respond to any attempts to disrupt public order.

He said, "crime, intimidation, violence, destruction of property and any attempt to undermine public safety will not be tolerated."

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President Cyril Ramaphosa has also sought to reassure South Africans and foreign nationals that the state is ready to deal with any unrest.

According to the presidency, security agencies have been placed on high alert following calls for coordinated demonstrations across the country.

The government has repeatedly stressed that immigration concerns must be handled through legal processes rather than vigilante action.

The growing uncertainty has already forced thousands of migrants to seek ways out of South Africa.

Large groups of people, mostly from Malawi and Zimbabwe, have gathered in Johannesburg and Cape Town while waiting for transport back to their home countries.

Many say they were forced from their homes after landlords asked them to leave or lost their jobs because employers feared becoming targets of anti-immigrant groups.

In an unusual move, several African governments have arranged buses and chartered flights to repatriate their citizens ahead of the June 30 deadline, reflecting the seriousness of the situation.

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The campaign is being driven by organisations including Operation Dudula and the March & March movement, both of which have long argued that undocumented migration contributes to unemployment, crime and pressure on public services.

Operation Dudula, whose Zulu name roughly translates to "push back" or "force out," has previously organised demonstrations outside businesses owned by foreign nationals, stopped people in public to demand identification documents and attempted to prevent foreign nationals from accessing government hospitals.

Another prominent figure behind the campaign is Nkosikhona Ndabandaba, popularly known as "Phakel'umthakathi." With more than 1.7 million Facebook followers, he has emerged as one of the loudest voices behind the June 30 mobilisation.

Speaking to CNN, Ndabandaba said he was the architect of the deadline.

In one widely shared video, he tells a Congolese man to leave South Africa without asking whether he is legally in the country.

"June 30 is the deadline, but you don't have to wait until then – leave now," he says, before adding, "I can't control the people of South Africa."

South Africa has experienced repeated outbreaks of xenophobic violence over the past two decades, often targeting migrants from countries including Zimbabwe, Mozambique, Malawi, Nigeria, Somalia and the Democratic Republic of Congo.

The deadliest attacks occurred in 2008, when at least 62 people were killed and tens of thousands displaced in nationwide riots targeting foreign nationals.

Since then, similar outbreaks have occurred periodically, prompting concerns from human rights organisations, neighbouring governments and the African Union.

Authorities have urged residents to remain calm and warned that anyone responsible for attacks, looting or intimidation will face arrest as security forces continue monitoring demonstrations across the country.