South African police deployed to head off unrest and protests on Tuesday, the unofficial deadline set by citizen-led groups for undocumented foreign nationals to leave that has already pushed thousands to flee.

Officers were out to prevent violence and looting, while hundreds of foreign nationals took refuge in several cities, urgently seeking help to leave.

At least four foreign nationals, two Mozambicans, one Ethiopian and one Malawian, have been killed in anti-immigrant violence in recent weeks. Several African governments have organised flights and buses to repatriate their citizens.

South Africa's Border Management Authority said about 25,000 had been repatriated in recent weeks.

Officials said around 15,000 Malawians had been processed for departure, while thousands more from Ghana, Mozambique, Nigeria, Zimbabwe and other countries had already left. Uganda has also announced plans to evacuate nearly 750 of its citizens.

As Tuesday’s unauthorized deadline arrived, thousands of people, mostly Malawians and Zimbabweans, also gathered in Cape Town and Johannesburg, waiting for assistance to go home.

Some said their landlords had evicted them or their employers had fired them, fearing fines from officials or attacks by vigilante groups.

"Rolling mass action"

The June 30 deadline was set by the anti-illegal immigration group March and March, whose leader, Jacinta Ngobese-Zuma, has called for "a national march to freedom, a rolling mass action" until undocumented migrants are deported.

"We are not calling for violence ... no one will be killed on June 30, and no looting will take place in our name," she said.

Concerned about a repeat of the unrest that struck five years ago, when around 350 people were killed in days of looting and riots, the government ordered a massive security deployment and warned against opportunistic crime.

The July 2021 unrest was sparked by the brief jailing of former President Jacob Zuma for refusing to testify to a commission probing corruption.

In the countdown to June 30, President Cyril Ramaphosa announced stepped-up government plans to combat illegal immigration and called on traditional leaders to use their "standing to calm tensions".

One of the continent’s wealthiest countries, South Africa is a magnet for migrant labour while grappling with an unemployment rate above 30%, high crime and a breakdown in services in many areas.

Previous flare-ups of violence targeting undocumented foreign nationals in South Africa have been deadly, with 62 people killed in riots in 2008.

But this is the first time that governments have simultaneously organised the repatriation of thousands of their nationals.

Groups campaigning against illegal immigration accuse foreign nationals of taking jobs, committing crimes and putting pressure on resources.