At least 24 vehicles have been set ablaze and foreign-owned shops looted in South Africa as anti-immigration protests descended into violence in two major cities, police say.

Clashes broke out on Thursday in Soweto, a sprawling township outside Johannesburg, the country's largest city, and Durban, a major port on the east coast.

The violence comes amid growing anger over a court ruling requiring the government to remove barriers that had prevented some migrants from applying for asylum.

South Africa has experienced repeated outbreaks of xenophobic violence, often targeting migrants from neighbouring countries.

Thursday's demonstration turned violent following allegations that a foreign national had assaulted one of the protesters in Durban. Three foreign nationals were arrested in connection with the alleged assault, police said.

In Durban, in the eastern province of KwaZulu-Natal, protesters gathered outside a government refugee reception centre demanding that it stop accepting asylum applications.

Police fired rubber bullets to disperse crowds as businesses in the city centre shut their doors.

"There were clashes between foreign nationals in the area and South African nationals," senior local police officer Xolani Fihla told state broadcaster SABC.

"At the present moment, I can confirm that no injuries have been reported," he added.

Police said 14 vehicles were torched in Durban and 10 in Soweto, where gunshots were also reported during confrontations between residents and foreign shopkeepers.

Acting national police commissioner Lt Gen Puleng Dimpane condemned the destruction of property.

In Orlando West, a neighbourhood of Soweto, residents had initially gathered to demand the closure of small convenience stores, known locally as spaza shops, operated by foreign nationals.

Protesters forced foreign traders out of some areas, while shops were attacked and a building was set on fire, local media reported. Police said reinforcements had been deployed to prevent further violence.

The authorities have promised to pursue those responsible for the destruction. The latest unrest follows a July ruling by South Africa's Constitutional Court, the country's highest court, which struck down restrictions preventing some people from seeking asylum because of how they entered the country or missed immigration deadlines.

The judgment means asylum seekers must be allowed to submit applications, even if they entered South Africa without the required documents.

It has prompted hundreds of people to gather at refugee reception centres, fuelling anger among anti-immigration campaigners who fear the decision will encourage undocumented migration.

Government spokesman William Baloyi told Reuters news agency that people had deliberately spread false claims about the judgment, creating the impression that undocumented migrants would automatically be granted legal status.

Baloyi insisted that the ruling does not automatically give migrants refugee status or the right to remain permanently in South Africa.

Officials say applications will still be assessed individually and applicants will remain subject to immigration checks.

The protests forced tens of thousands of migrants to flee, with some returning home through repatriation programmes organised by their governments.

South Africa has struggled with xenophobic attacks for nearly two decades. In 2008, more than 60 people were killed and tens of thousands displaced during widespread attacks on foreign nationals.

The latest unrest comes against a backdrop of widespread poverty, deep inequality and unemployment affecting roughly a third of the workforce.

Migrants are frequently accused of taking jobs, contributing to crime and placing pressure on public services, although researchers say such sweeping claims are not supported by evidence.

Despite its economic difficulties, South Africa remains one of the continent's main destinations for migrants seeking employment, safety and better opportunities.