Nigerian President Muhammadu Buhari is visiting South Africa this week to promote ties between Africa's two largest economies.
The trip comes at a time when relations have deteriorated following a rise in attacks on foreigners in South African cities, including against Nigerians.
In response, hundreds of Nigerians have left South Africa fearful of the violence and Mr Buhari is expected to address a meeting of some of those still living in the country.
So how common are attacks against migrants and are they on the rise?
Attacks against foreigners
The South African government does not collect data on attacks or threats against foreign nationals.
However, the African Centre for Migration & Society (ACMS) has monitored these attacks across South Africa since 1994. Its Xenowatch tracker collates media reports as well as information from activists, victims and observers.
Violent attacks peaked in 2008 and again in 2015.
Data for 2019 (to late September) already shows that the number of attacks is approaching the level of 2015.
In 2008, there was a wave of attacks across the country against refugees and migrants - more than 60 people were reported to have been killed and thousands displaced.
In 2015, there were outbreaks of violence against non-South Africans, mostly in the cities of Durban and Johannesburg, which led to the deployment of the army to deter further unrest.
In March, the government launched an initiative to raise public awareness and improve access to services for victims of discrimination.
Human rights groups welcomed it, but said that the government needed to publicly recognise attacks on foreigners as xenophobic.
In a statement published in October 2018, South Africa's main opposition party, the Democratic Alliance, blamed the governing ANC party for a "scourge of xenophobic violence".
Where are the migrants from?
About 70% of foreigners in South Africa come from neighbouring Zimbabwe, Mozambique and Lesotho.
The remaining 30% is made up of people from Malawi, UK, Namibia, eSwatini, previously known as Swaziland, India and other countries.
There are an estimated 3.6 million migrants in the country, a spokesperson for South Africa's national statistics body told the BBC, out of an overall population of well over 50 million.
How do different regions compare?
Gauteng province, which includes South Africa's largest city Johannesburg and the capital Pretoria, has the highest rate of violence against foreign nationals, followed by the Western Cape, according to the ACMS. KwaZulu-Natal, where Durban is situated, is third.
Attacks have mainly taken place in large cities, but they have also been reported in smaller towns and rural areas.
The violence is often triggered by local disputes, with migrants being accused of taking jobs away from South Africans.
Foreign-run shops have been looted and destroyed.
The country has experienced poor economic performance, with officially recorded unemployment at more than 27% at the end of last year.
And more widely, the country has one of the highest murder rates in the world.
"The causes are poverty and has its roots in apartheid," says Sharon Ekambaram, who runs the refugee and migrant rights programme for Lawyers for Human Rights.