Thirty-four workers at AngloGold Ashanti's Vaal river operations have been treated for minor injuries and released from hospital following the earthquake in Orkney, North West, the company said on Wednesday.

"A total of 34 miners were treated and discharged. Colleagues who were underground when the earthquake happened were all safely brought to the surface," said spokesman Chris Nthite.

One person was killed when a 5.5 magnitude earthquake hit shortly after noon on Tuesday, causing scares in mining operations and evacuations in parts of the country.

The quake, one of South Africa's largest magnitude earthquakes in the past decade, was felt as far way as Mozambique and Botswana.

The Council for Geoscience said its epicentre was in the Orkney region.

More tremors, aftershocks and possibly a second quake of the same magnitude were expected in the coming days, but it was unknown when.

Nthite said work had not commenced at its affected mines.

Engineers were inspecting the shafts' infrastructure to ensure safety.

"Safety is the priority. No worker will go underground until it is safe to do so. Engineers will be able to tell us how the situation is underground," Nthite said.

The company's West Wits operations were not affected.