Four more people have tested positive for the coronavirus in South Africa.

National health minister Dr Zweli Mkhize on Monday confirmed the additional cases, meaning seven people have now tested positive.

The cases are all linked to the 10 people who recently went on a skiing trip to Italy.

"There have been further numbers of people who were part of this trip who have found to be positive," he said. "These individuals have come in as couples and we asked them to be in quarantine. At this point, four of them have now also tested positive."

Of the additional four, he said two were a couple from the uMgungundlovu area of KwaZulu-Natal. They have been placed under quarantine and have not yet been admitted to hospital.

"The woman had symptoms on arrival in South Africa. The man did not have symptoms, but the tests have come out positive," said Mkhize.

Another case is that of a 45-year-old man from the Pietermaritzburg region. Swab tests also came back positive, with the swabs taken after he showed symptoms of the virus.

The fourth new case was of a 38-year-old man, also from Pietermaritzburg.

On Thursday, Mkhize confirmed that SA's first confirmed case of Covid-19 was a 38-year-old man from Hilton who, together with his wife and eight other people, had travelled to Italy. The group returned to SA on 1 March and he tested positive for coronavirus on March 5.

On Saturday, Mkhize confirmed that a 39-year-old Gauteng woman, who was part of the group of 10 who had travelled to Italy, had tested positive. On Sunday, he advised that SA's third positive case - the wife of the Hilton man - was also positive. The couple's children had tested negative.