Two Mitchell's Plain schools were evacuated yesterday when a teargas-like substance leaked from adjacent Denel explosives and ammunition factory, making hundreds of pupils ill.

Education MEC André Gaum last night criticised Denel for its handling of the incident, as they had not informed the schools or surrounding communities about the hazardous leak.

Denel Group spokeswoman Thembi Tulwana last night refused to comment as she did not have the information "readily available".

Gaum said the Disaster Management had undertaken to investigate what had happened.

Hundreds of pupils at Oval North High School and Beacon Hill Secondary School in Beacon Valley complained of stomach and eye problems yesterday morning.

When police checked for gas leaks at the schools and found none, they went to the factory.

Emergency Services deputy director and medical doctor Wayne Smith said police found the source of he leak at a division of Denel Swartklip Products, responsible for the manufacture of ammunition and explosives.

Smith said some of the children had started vomiting and their eyes had started to water because of the chemicals in the air.

"When we heard of reports from another school that learners were experiencing similar symptoms, police told us that the Swartklip factory had a problem with one of its production reactors and a chemical was leaking out," Smith said.

The chemical, CS Irritant, was "almost like teargas" but was registered at very low levels, said Smith.

With acknowledgements to A'eysha Kassiem and the Cape Times.