At least five people have died in a wave of violence against foreigners in Durban, South Africa, while thousands more were driven out of their homes in the coastal city. Hundreds of miles away, in the commercial hub of Johannesburg, immigrant shopkeepers fearing copycat attacks have closed their businesses.

While no widespread violence has been reported in the city, threatening messages have been circulating on social media. As the Mail and Guardian reports, concerned residents have been issuing messages of their own, taking to the messaging app WhatsApp and SMS text messages to alert others to be vigilant. According to the Mail and Guardian, an Ethiopian street vendor received a message saying the following:

It seems that there are attacks planned for Johannesburg on Wednesday: CBD, Hillbrow, Berea and Yeoville. [On] Wednesday, Zulu people are coming to town starting from Market [street] their mission is to kill every foreigner on the road please pass this to all your contacts in case they come people should be on alert.

More than 60 people were killed in xenophobic attacks in Johannesburg in 2008. The violence, mainly targeting South Africa’s immigrants (who make up 10% of the country’s population), is blamed largely on a general atmosphere of discontent, bred by high unemployment rates and rising inequality.

In an attack caught on video today by a South African journalist in Johannesburg, a taxi driver got into an altercation with an Ethiopian national. Indications are that the fracas was motivated at least in part by xenophobia: