As Kyodo reports referring to Kumamoto city administration, at first children had abdominal pain and diarrhea. Later, 34 children were diagnosed with signs of poisoning. Many of them were hospitalized. All the victims are students of Giotto municipal elementary school , reports RIA Novosti.

A probable cause of the mass poisoning are low quality rice balls called "onigiri" with tuna chips. It is known that the product was produced in one of the local companies on May 6. In total 100 rice balls were produced on that day, 70 of which were later sent to the elementary school Giotto. During the examination of the onigiris, Staphylococcus bacteria were detected, which can be a cause of a number of deadly diseases. At the same time, according to the hospital staff, there is no threat to children's health.