Residents in several suburbs in Cape Town confirmed on social media on Saturday night that they had felt an tremor.
The American Geological Survey (USGS) reports that the earthquake of 6.2 hit South Africa at around 19:10 at a depth of 10 km. No tsunami alert has been issued and no injuries have been reported so far.
According to the National Center for Seismology, the quake occurred about 1,600 km south-southeast of Cape Town.
The Cape Town Metro Council on Saturday called on people to report any possible impact of the incident to the Public Emergency Communications Center by calling 021 480 7700 on a cellphone, or 107 from a landline.