Forty-two children have been sickened in a food poisoning incident at a kindergarten in north China's Hebei Province, local authorities said Friday.

On the afternoon of Oct. 15, 42 children began showing symptoms of diarrhea and fever at the Minzu Kindergarten, located in the Qiaoxi district of the city of Zhangjiakou, according to a statement from the publicity department of the district committee of the Communist Party of China (CPC).

All of the sickened children were taken to a local hospital for treatment. As of Friday, four of the sickened children remain in the hospital, while the others have all been discharged, according to the statement.

A test of the kindergarten's food, drinking water and tableware showed the incident was caused by a minor bacteria infection, it said.

In another food poisoning case, 22 students became ill on Monday after eating food contaminated by rat poison at the Xiaoliuzhai Primary School in the city of Wenshan in southwest China's Yunnan province, resulting in one death. Five of the students remained in serious condition as of Wednesday.