"Upon medical examination, 17 were admitted for overnight observation, while the remaining 24 were discharged home in a satisfactory condition," regional health authorities for Gauteng said.

Also on Monday, a group of 10 people including eight children were referred to a different hospital in the same province.

Health authorities say this is all part of an "alarming" overall rise in food poisoning cases - with a total of 863 such incidents reported since last October.

They're advising parents and guardians to take greater care to protect children, and say anybody with food-poisoning symptoms - such as nausea, diarrhoea, vomiting and stomach aches - should visit their nearest health centre as quickly as possible.