A teacher was arrested after she allegedly poisoned 23 children by putting nitrite in their food, the incident happened in the Henan Province of China.

The 23 students were from the Mengmeng Kindergarten in Jiaozuo City, they fell ill after eating the porridge that was supplied by the kindergarten school on Wednesday.

7 kids are still admitted at a hospital and one other child is still being treated. Officials said that 15 children have been discharged from the hospital.

After the police got to know about the mass illness, they started an investigation that revealed the teacher put nitrate in the porridge that was eaten by the students.

Nitrite is a carcinogen that is used in fertilizers, ammunitions, explosives, and food preservations.

Eating high amounts of nitrate can lead to headaches, vomiting, increased heart rates, and sometimes death.

Li, a parent, said that he was called by the school on Wednesday and was informed that his child vomited and fainted, after he arrived at the school, he found his child unconscious.

Li said, “The vomit was all over (their) pants. There were other children who were also throwing up, and they looked pale.”