Health authorities in northwest China's Shaanxi Province are investigating a suspected food poisoning case in a vocational school, in which 81 students showed symptoms of diarrhea or vomiting since Thursday.

None of these students in the Shaanxi Railway Engineering Vocational School have shown severe symptoms, according to the school's clinic.

The students showed symptoms after dining in the school canteen on Thursday, when the school celebrated its 35th founding anniversary. The students were offered a free lunch, which included rice, chicken leg, egg, bean curd with fried pork.

The health department in Weinan City, where the school is located, have taken samples of the canteen food and the patients' excrement and vomits for pathologic tests.

(Xinhua News Agency November 8, 2008)