The department said 496 students and two wardens at SM Teknik Tunku Abdul Rahman Putra were “exposed” to a batch of “fried tandoori chicken” served for lunch on July 12 by the school’s canteen.

Of the 498 people, it said 30 students fell ill and were forced to seek treatment at the Penang Hospital and Penaga health clinic.

“The kitchen has since been sealed under the Prevention and Control of Infectious Diseases Act 1988, pending further investigation,” the department’s food safety and quality division said, adding that no one was admitted to the hospital overnight.

“The Northeast health office is investigating the exact cause of the food poisoning. Samples of food have been collected for lab analysis and results are pending,” it said.

It also checked the food handlers and the environment.