One hundred and seventy one students in a vocational school in northeast China's Heilongjiang Province may have come down with food poisoning Wednesday evening, local health authorities said on Thursday.

The students developed symptoms of nausea and vomiting on Wednesday evening after they had supper at Qiqihar Medical School.

A total of 171 students were taken to the No. 2 Hospital affiliated to Qiqihar Medical College from Wednesday night to Thursday noon, said a doctor at the hospital.

One hundred and seventeen students have gone back to school, and the rest who are still receiving medical treatments are stable, said the doctor.

Preliminary investigation showed that the students may have come down with food poisoning, but local health and disease prevention and control departments have taken food samples from the school meals over the last several days for further testing.

The municipal government of Qiqihar has ordered a check-up of food safety at all schools immediately after the incident.

Earlier on Monday, 223 high school students in northwest China's Shaanxi Province were hit by food poisoning after they ate their school lunch.

(Xinhua News Agency September 22, 2006)