One of South Africa’s richest suburbs may be the target of a terrorist attack this weekend, according to an alert posted on the website of the US Embassy.

“The US government has received information that terrorists may be planning to conduct an attack targeting large gatherings of people at an unspecified location in the greater Sandton area of Johannesburg, South Africa, on 29 Oct.,” the embassy said in a statement. “There is no further information regarding the timing, method, or target of the potential attack.”

The embassy advised its staff to avoid crowds of people and other large public gatherings in the specified area over the coming weekend.

Many of the biggest companies in South Africa, including financial services group FirstRand Ltd., chemicals company Sasol Ltd., insurer Discovery Ltd., Bank of America Corp., Citigroup Inc., law firms and international auditing firms such as EY have their headquarters in Sandton. There is also a multi-faceted retail space in the suburb, which attracts crowds of tourists and locals on weekends.

Liberty Two Degrees Ltd., the operator of retail properties in Sandton — also known at the richest square mile in Africa — said it’s taken sufficient security measures in and around the Sandton City mall, Nelson Mandela Square, offices, hotels and the Sandton Convention Centre.

The South African government is continuously assessing threats and will inform the public of any imminent attack, President Cyril Ramaphosa’s spokesman, Vincent Magwenya, said in a statement.

“We continue to monitor for any threats to our citizens, our nation and our sovereignty,” he said. “Threats are assessed continuously and are acted upon to ensure the safety of all.”