One hundred and forty-one primary school students fell ill after eating at their school on Monday in north China's Shanxi Province, local authorities said.

The sickened students study at the Xinxiao Bilingual Experimental School in the province's capital of Taiyuan, according to a spokesman from the city's Xinghualing District government.

The students, aged from eight to 12, experienced stomachaches and nausea and have been sent to seven major hospitals in Taiyuan.

Initial tests showed the cause to be a food-borne gastrointestinal infection, with treatment currently under way, said Li Runsen, director of the medical affairs office of the Shanxi Provincial Children's Hospital.

Twenty-four of the students have already left the hospitals, while the other 117 are continuing to receive treatment. Twelve of the students were described as being in "relatively serious" condition, with persistent fevers and stomachaches, Li said.