Drug abuse has become so rife in schools that principals are forced to test pupils daily.

In some schools breathalysers are being used to test if pupils have been drinking alcohol during class and on special events days.

Anti-drug activists and organisations that are called upon to conduct the tests said drug testing at both private and public schools are becoming more frequent with more schoolchildren testing positive.

In Chatsworth, south of Durban, between 20 to 30 high school pupils test positive for dagga each week.

Sam Pillay, director of the Chatsworth Anti-drug Forum and KwaZulu-Natal Anti-Substance Abuse Forum deputy chair, said if a principal from one of the 80 schools in the area suspects a pupil has used drugs, the parent is contacted and instructed to take the child to the anti-drug centre for a test.

The high number of girls that tested positive for dagga warranted a separate class for them.

Pillay said while there were "a few" primary school pupils who had tested positive for dagga, the worst affected were high school pupils aged between 13 and 16.