Iran's President, Ebrahim Raisi, on Wednesday ordered a time-bound investigation into the poisoning of schoolgirls in different Iranian cities, Anadolu News Agency reports.
Chairing a cabinet meeting in the capital, Tehran, Raisi instructed Interior Minister, Ahmad Vahidi, to find the cause of the mysterious poisoning, which has sent hundreds of schoolgirls to hospitals in recent weeks, "as quickly as possible".
He also urged the ministries of health, information and related departments to provide assistance to the Interior Ministry in investigating the case that is sending shockwaves across the country.
Hundreds of schoolgirls have been hospitalised in different cities across Iran since November last year in what has been described as a wave of a mysterious illness.
Although many parents have suspected "poisoning" as the cause of their hospitalisation, authorities probing the matter have no conclusive explanations, so far.
Earlier this week, Deputy Health Minister, Younes Panahi, said "some people" were poisoning schoolgirls in the central Iranian city of Qom to disrupt their education.
He stressed that the poisoning of schoolgirls was caused by "chemical compounds" that are not contagious while ruling out any "external causes".
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His remarks came shortly after Iran's Prosecutor-General, Mohammad Jafar Montazeri, ordered a judicial probe into the issue, following protests in the city of Qom, a popular pilgrim site.
The first incident of this mysterious poisoning was reported in November last year, when at least 18 schoolgirls were transferred to a hospital in Qom after complaining of symptoms such as nausea, breathing problems, cough and body pain.
In the latest incident reported by local media last week, at least 15 schoolgirls were admitted to a hospital in Qom after complaining of respiratory problems.
From Qom, it has gradually spread to other cities in recent days, including Tehran.
On Wednesday, local media reported some cases of poisoning at a few schools in western Tehran, adding that their condition was "stable".
There were also reports on Wednesday about the poisoning of students at seven girls' schools in northern Ardabil city after "smelling gas or something similar". There have been similar reports from other cities as well, including Kermanshah.
Addressing a press conference in Tehran, Interior Minister, Vahidi, said no one had so far been paralysed as a result of the poisoning.
He also refuted a local media report about arrests in connection with the poisoning of schoolgirls, saying the claims are designed to "create a psychological atmosphere among students and families".
Tehran's newly-appointed Police Chief, Ahmedreza Radan, also said no one has been arrested yet, adding that efforts are under way to "find the origin of the issue".
It comes after months of protests in Iran, which were marred by violence. The unrest was sparked by the death of a 22-year-old Iranian woman while in police custody in mid-September.