Dozens of Iranian schoolgirls across five provinces were taken to hospital on Saturday in the latest wave of suspected poisoning attacks, local media reported.
Hundreds of cases of respiratory distress among schoolgirls have been reported in Iran over the past three months, mainly in the holy city of Qom, south of Tehran.
Tasnim and Mehr news agencies reported the latest suspected poisonings in the western province of Hamedan, Zanjan and West Azerbaijan in the north-west, Fars in the south and Alborz province in the north.
Dozens of schoolgirls were taken to hospitals for treatment, the reports said, adding all pupils were in generally good health.
On Friday, President Ebrahim Raisi said he had asked the ministers of intelligence and interior to follow up on the cases, calling them “the enemy's conspiracy to create fear and despair in the people”.
Foreign Ministry spokesman Nasser Kanaani said an investigation into the poisonings was “one of the immediate priorities of the government, to alleviate the concerns of the families and to hold perpetrators accountable”.
The UN and Germany on Friday called for investigations into the reported poisonings.
The UN's human rights office is “very concerned about these allegations that girls are being deliberately targeted under what appear to be mysterious circumstances”, UN spokeswoman Ravina Shamdasani said.
“The reports of schoolgirls being poisoned in Iran are shocking,” German Foreign Minister Annalena Baerbock said on Twitter.
On Wednesday, at least 10 girls' schools were targeted with poisoning attacks, seven in the north-western city of Ardabil and three in the capital Tehran, according to media reports.
Last week, Iran's Deputy Health Minister, Younes Panahi, said the poisonings were aimed at shutting down education for girls.