CHONGZHOU, Sichuan Province -- About 200 students who contracted food poisoning after eating lunch in a primary school in southwest China's Sichuan Province last Friday are still in hospital. The school suspended classes on Monday to deal with the incident.

Chen Gang, vice mayor of Chongzhou City, where Chongzhou City Experimental Primary School is located, told Xinhua that all students with food poisoning symptoms have been hospitalized for treatment and examination. Many school staff were at the hospital taking care of the sick kids.

The school has been temporarily closed down. School sources said that they would have to wait for two thirds of the students to recover, and then to decide when to restart classes.

More than 300 of the 800 pupils who ate lunch at school on Friday, the first day of the new term, developed symptoms of headache, fever, vomiting, stomach-ache and diarrhoea.

About 100 students whose symptoms were relatively minor symptoms have already left hospital after medical examinations proved satisfactory.

No deaths have been reported, confirmed local authorities.

The cause of the food poisoning is being investigated.