The Iranian government has intensified its crackdown on media and individuals who speak out about a wave of poisonings that has sickened hundreds of students across the country over more than three months.
The poisonings, which first affected girls' schools, have now spread to boys' schools and university dormitories.
On March 6, Tehran prosecutor's office announced that court cases have been filed against journalists, media managers and individuals who have spoken out against the poisoning attacks.
"In the past week, court cases were filed against the managers of Hammihan newspaper, Roidad 24 news website and Shargh newspaper, as well as individuals including Azar Mansouri, Sadegh Zibakalam, and Reza Kianian," it said.
Meanwhile, the judiciary’s Mizan Online website quoted Tehran prosecutor Ali Salehi as warning "those who spread lies and rumours" about the poisonings that "they will be dealt with decisively and legally."
Seyed Ali Portabatabaei, a reporter for Qom News and one of the first journalists to have reported on the poisonings, was arrested prior to the announcement.
Pressure on the media and individuals trying to bring attention to the attacks has raised concerns about the government's commitment to transparency and accountability in its investigation into the poisonings.
Calling the poisonings a "heinous act" and a "crime against humanity,” the Iranian Medical System Organization has urged the government to take action to prevent future attacks and to hold those responsible accountable.
The Coordinating Council of Educators' Trade Unions has warned that if educators and other members of society do not resist this systematic attack on education, more violent acts are likely to occur.
The authorities have yet to provide a convincing explanation about the origin and exact nature of the attacks
On March 6, the White House called for a “credible independent” investigation into the matter and for accountability.
"If these poisonings are related to participation in protests, then it is well within the mandate of the UN independent international fact-finding mission on Iran to investigate," said White House spokeswoman Karine Jean-Pierre.
She referred to the mission established in November to investigate human rights abuses linked to nationwide protests that have swept Iran for more than five months.
Some Iranians have suggested that the poisonings could be an attempt to force the closure of girls’ schools or a retaliation for students and women leading the anti-government protests sparked by the death of a 22-year-old woman, Mahsa Amini, in the custody of morality police.
While Iranian political figures and activists have described the wave of poisonings as "chemical" and "biological" attacks, officials have only recently admitted there may be a problem.
So far, no arrest has been announced in relation to the poisonings, which have sparked outrage among the families of the affected students and Iranian society at large.