More<a href="https://www.thenationalnews.com/mena/iran/2023/03/05/iran-schoolgirl-poisoning-crisis-worsens-as-officials-confirm-50-schools-affected/" target="_blank"> school poisonings</a> have been reported in Iran, prompting fears of further repression as the authorities vow to strictly enforce mandatory hijab rules. Poison attacks have been reported in at least five girls' schools at the end of the <a href="https://www.thenationalnews.com/mena/iran/2023/03/21/in-iran-people-fighting-against-dictator-with-fire-of-nowruz/" target="_blank">Nowruz holidays,</a> including in Isfahan, Urmia and Tabriz. Twenty schoolgirls in Tabriz were taken to hospital with breathing difficulties, the head of the provincial emergency department told the semi-official Isna news agency on Tuesday. The first poisonings were reported in November while the country was rocked by mass anti-government demonstrations. Activists and parents said the government is behind the attacks, while Tehran has placed the blame on protesters. More than 5,000 pupils, mostly girls, have suffered from a variety of symptoms, including nausea and shortness of breath, after reporting "unpleasant" odours. Iran's <a href="https://www.thenationalnews.com/mena/iran/2023/03/08/irans-top-sunni-cleric-calls-for-school-closures-as-protesters-blamed-for-poisonings/" target="_blank">senior Sunni cleric</a> has called for schools to be closed in light of the poisonings. It comes as Tehran has vowed to show no mercy to women who breach the requirement to wear the hijab in public places, even <a href="https://www.thenationalnews.com/mena/2023/04/03/iran-universities-to-withhold-services-from-unveiled-students/" target="_blank">barring university students</a> from accessing services. Professors at Shiraz University have also been instructed to question female students who are not wearing the hijab. The move will destroy relationships between teachers and students and put them "at war", lawyers said. Women have defied the hijab rule in greater numbers since the protests began in September. Women burnt hijabs in the streets and chanted against Iran's supreme leader Ayatollah Ali Khamenei after the death of Mahsa Amini in police custody. She was detained in Tehran three days earlier for allegedly wearing her hijab "improperly". Security forces have killed at least 537 protesters since September, according to a new tally from Iran Human Rights. The UN estimates more than 18,000 people have been arrested, while Tehran says it has pardoned 22,000 people over the protests. It has executed four men for joining the demonstrations after holding swift trials without due process.