As a result of the warnings major malls in Johannesburg and Cape Town have upped their security and say they are consulting closely with the police and State Security.
It was not immediately clear what triggered the warnings. Security officials say there are no known militant groups operating in South Africa. It has only a small Muslim population.
The Muslim Judicial Council has warned that the increased security could strain relations between Muslims and others. It has urged US authorities to “back up” their claims.
On Saturday the US diplomatic mission to South Africa cautioned that Islamic State had called on its followers to carry out terror attacks during Ramadan. It warned that shopping malls in Cape Town and Johannesburg that were frequented by US citizens would be the likely targets.
The response of South Africans to the warnings has been mixed. A poll of Times Live readers yesterday found that 39.14% would avoid malls and tourist attractions. The rest said they were “not worried”.
Over the weekend, the US government had issued a terror alert for South Africa after the terrorist group Islamic State made a public call for its adherents to carry out terrorist attacks globally during the upcoming month of Ramadaan.
“The US government has received information that terrorist groups are planning to carry out near-term attacks against places where US citizens congregate in South Africa, such as upscale shopping areas and malls in Johannesburg and Cape Town,” said US Embassy spokeswoman Cynthia Harvey.
“Protection of US citizens overseas is among our top priorities. When we receive specific, credible, non-counterable threat information, it is our worldwide policy for US embassies and consulates to share the information. We are co-operating with local authorities, as we do in any investigation into terrorist threats around the world,” she said.