Marijuana consumption is legalised in South Africa but under restrictions. / Photo: Reuters

Police in South Africa have launched investigations over an incident where 90 children at a school north of the capital, Pretoria, were taken to hospital after eating muffins thought to be laced with cannabis.

The learners at Pulamadibogo primary school were rushed to local hospitals on Wednesday after experiencing nausea and stomach cramps and vomiting, the Gauteng's province education department said.

They thought to have bought the muffins from a street vendor while on their way to school.

"Indeed, this is concerning for us and we call for patience while investigations are underway and learners are recovering," said Gauteng Education Member of the Executive Council (MEC) Matome Chiloane.

"We implore learners to be vigilant of what they purchase and consume."

Police were called at the school during the incident and the suspected vendor identified.

South Africa's highest court in 2018 legalised the use of cannabis by adults in private places. It also legalised the growing of marijuana for private consumption.

TRT Afrika and agencies