About 650 girls have been poisoned by toxic gas in Iran, in what many believe is a deliberate attempt to force their schools to shut.
No death has been reported but several girls have suffered respiratory problems, nausea, dizziness and fatigue.
The deputy health minister said that it is evident that some people wanted all girls schools to be closed down.
The prosecutor general last week announced that he was opening a criminal investigation, noting that the only available information indicated the possibility of criminal and premeditated acts.
The first poisoning took place on November, when 18 students from the Nour Technical School in the religious city of Qom were taken to hospital.
Since then, more than 10 girls’ schools have been targeted in the surrounding province.
At least 194 girls are reported to have been poisoned in the past week at four schools in the city of Borujerd, in the western province of Lorestan.
The poisoned girls have reported the smell of tangerine or rotten fish before falling ill.
Earlier this month, at least 100 people protested outside the governor’s office in Qom.
A woman declared that this is war declared because they are targeting girls’ high school in Qom to force the girls to stay at home.
Some parents have said their children were ill for weeks after the poisoning.
One of the parents, a mother, has urged other parents not take their children to school noting that her own child is in a hospital bed and her limbs are weak and numb, cannot feel anything even when pinched.
At a news conference on Sunday, Deputy Health Minister said the girls had been poisoned by chemicals that “are not military grade and are publicly available”.
The poisonings have been concentrated in Qom.
Some Iranians have speculated that schoolgirls being poisoned is “payback” for their participation in the unrest.
Social media was flooded with videos showing schoolgirls ripping off their headscarves and chanting anti-establishment slogans.
Others have speculated that the poisonings are the work of hardliners who want to “copy” the Taliban and the m
Boko Haram by terrorising parents to stop sending their girls to school.
The comments of one schoolgirl, who says she has been poisoned twice, at the meeting with Qom’s governor earlier this month highlighted how vague and misleading some of the statements from the authorities have been.