Zuma was speaking in Cullinan at the launch of the integrated school health policy, a pilot project of the proposed national health insurance scheme.

The project will send mobile clinics to schools to offer immunisations, eye screenings, dentistry and mental-health services to pupils.

High school pupils will be able to get contraceptive services, including condoms, from the mobile clinics, provided the school governing body approves.

But Deputy Minister of Education Mohamed Enver Surty stressed that there was "no way" that condoms would be placed in dispensers in schools.

The last annual survey by the Department of Education found that only 40% of school governing bodies functioned adequately. Surty said their members would be given training on handling sexual health issues.

Zuma said parents should not simply hope that their children were not having sex and "nothing will go wrong".

"One day you will be surprised," he warned.

He said many teenage girls had to leave school because they were pregnant.

"We know that this subject makes parents uncomfortable, understandably so. But we have to face the reality that some pupils are sexually active, no matter how much this knowledge troubles us as parents."

Health Minister Aaron Motsoaledi said he did not want the new health plan to centre on the media's fascination with condoms because "it goes far beyond that".

"It is a comprehensive dental screening, primary care, immunisation drive."

The hope is to overcome the faults that troubled previous initiatives, including the inequitable distribution of resources, lack of collaboration between the departments of health and of education, too few follow-up visits by nurses, and insufficient staff.