About 90 pupils from a boarding school in north China's Inner Mongolia Autonomous Region have been sent to hospital after eating at their school canteen on Wednesday, a local health official said on Thursday.

The children felt bellyache and nausea after eating supper on Wednesday at the Hada Yingge Primary School in the Bairin Left Banner, Chifeng City, said Shao Jianguo, head of the banner's Health Bureau.

They were sent to hospital from Wednesday night to Thursday morning.

To date, 32 pupils still remain under observation at the hospital and the rest were discharged, Shao said.

Local health authorities said preliminary investigations have shown it was a food poisoning incident. All the foods stored in the school canteen have been sealed off for further tests, the official said.

The primary school has about 700 students.

(Xinhua News Agency September 7, 2007)