Twenty-eight primary school pupils in east China's Anhui Province were rushed to hospital after eating a school meal consisting of expired instant noodles Thursday morning, said the local education authority Friday.

The pupils had probably suffered mild food poisoning, complaining of stomach aches after eating the noodles for breakfast provided by the Hushan Primary School in Xiaoxian County, said Meng Xiangyong, deputy head of the local education bureau.

The instant noodles, eaten by over 100 pupils at the school, were found to have exceeded their shelf life by more than 10 days, Meng said.

The children had received medical treatment and were discharged from hospital that afternoon, after their symptoms subsided.

The local food quality authority is investigating the case, while the police are tracking the source of the expired food.