Four people working for a bakery were detained by police after 121 children became ill with food poisoning in three kindergartens in Nanchang, capital of eastern China's Jiangxi Province, according to the municipal government.
The municipal food and drug authority found the kindergartens had allowed children to eat contaminated strawberry cake from Jili Bakery.
Police closed the bakery, which did not have legitimate food production permits.
As of Thursday morning, 32 children were hospitalized, with the rest discharged. The sick children showed symptoms of vomiting and abdominal pains Tuesday afternoon.
Police are working with municipal health and education departments to investigate.
Samples of the cake have been sent for lab tests.
