The US embassy has raised the alarm of a "possible terrorist attack" in the greater Sandton area in Johannesburg over the weekend.
In a security alert to US citizens in South Africa, it said, "terrorists may be planning to conduct an attack targeting large gatherings of people at an unspecified location" in Sandton on Saturday.
"There is no further information regarding the timing, method, or target of the potential attack," the alert read.
The embassy advised that individuals avoid crowds of people and other large public gatherings in that area on Saturday and Sunday.