More than 40 students from the No.4 Middle School of Tongzi County in southwest China's Guizhou Province were suffering from food poisoning, said sources with the county education bureau on Monday.

The preliminary diagnoses by local health department indicates they had eaten deteriorating food and were receiving treatment in hospital, said the sources.

"Students were vomiting and feeling sick one after another after they attended the flag-raising ceremony this morning," said Yang Chaojian, principal of the middle school.

The school authorities contacted the sanitation and epidemic prevention department immediately and rushed the sick students to a local hospital. More than 90 students were receiving treatment and over 40 students have developed evident symptoms of food poisoning.

The department said the deteriorating polished glutinous rice the students ate was believed the cause resulting in the food poisoning. The middle school has closed all its five breakfast cafeterias.

(Xinhua News Agency June 28, 2005)