JOHANNESBURG (AFP) - The United States embassy in South Africa warned on Tuesday (Sept 8) of a "terrorist threat" to US interests in the country, and advised its citizens to be on heightened alert against attack.

The security message issued by the embassy in Pretoria said there was no information of the possible timing or target in South Africa, which has escaped the militant Islamist attacks seen in several other African countries.

"Extremists may be targeting US interests in South Africa, to possibly include US Government facilities and other facilities identifiable with US business interests," the embassy statement said.

"Remain aware and vigilant of your surroundings... Be vigilant and take appropriate steps to enhance your personal security."

The South African government was not immediately available to comment.