Families have protested in Tehran after several hundred cases of gas poisoning of girls in more than 52 schools over the past three months.

The “chemical compounds” made them vomit and become dizzy.

More than a thousand students have fallen ill and an unknown number have been hospitalized.

In his first comments on the mysterious poisonings, Iran’s Supreme Leader Ayatollah Ali Khamenei said those behind the poisonings should face “severe punishment”.

He also said it is “a serious and unforgivable crime and there will be no amnesty for the perpetrators”.

Late Sunday, Iranian President Ebrahim Raisi condemned the poisoning cases as “a new conspiracy by Iran’s enemies.”

This action, Raisi said, was intended to “instill fear in the hearts of students, children and their parents”.

Justice Gholamhossein Mohseni Ejei said on Monday that anyone arrested would be tried and charged with “corruption on earth” which would lead to the death penalty.

More than 700 similar cases were reported in the southwestern province of Khuzestan on Sunday.

Authorities have not yet identified the gas used or the reasons why the girls were attacked in this way.

Last week, Deputy Health Minister Younes Panahi said the suspected attacks were aimed at shutting down education for girls.

The poisonings began last November, amid anti-government protests that erupted across the country in September following the death of a young woman, Iranian Kurdish Mahsa Amini, aged 22, after she was arrested for violating Iran’s strict dress code. code for women.