Malawian nationals gathered outside Malawi's Consulate General in Johannesburg on Thursday, saying they feared for their safety as a June 30 ultimatum from anti-migrant groups drew closer.

Footage shows families camped on the pavement outside the consulate, some with bags, blankets and children beside them. Women are seen carrying infants, police officers taking down names, and people queueing for food.

Many said landlords had told them to leave, fearing protesters could damage their properties.

"The landlord says, ‘We can't protect you. The situation is worse, so you must go.’ So we have come here for help," Bertha Henry, a Malawian national, said.

"We're here in the cold with the children. Other [women] are pregnant, but we are outside. We are not eating, so we need our government to help us fast to go home so that we can survive for our lives," she continued.

Mussah Hamuzah, another Malawian national waiting outside the consulate, said anti-migrant protesters had forced people to leave their neighbourhoods.

"They have been [to] our location, and when they have been there, they chase us, and they (Malawians) just have the money from there to here only, and these people are here," he said.

"When they protest here, they're gonna burn my house, so 'I don't want you here. Please leave!' And these people, they leave," he added.

The deadline, aimed at undocumented foreign nationals, was not issued by the South African government but has spread fear through migrant communities, with several countries already repatriating citizens from South Africa.

South African police have tightened security ahead of June 30, while President Cyril Ramaphosa has rejected the deadline and warned against attempts to destabilise the country.