Eight students have been deprived of education for up to two years or exiled to other cities as punishment for protesting the wave of chemical attacks in Iran's universities and schools.

The students of Tabriz University of Medical Sciences received the punishments for participating in a rally back in March against attacks which have affected thousands of girls across the country.

Last week, over 2,000 students signed a petition demanding the cancellation of the heavy sentences of the disciplinary committee against their colleagues.

Close to 300 schools were targeted in the past Iranian year without any apparent serious effort by the government to identify and pursue the perpetrators, nor to explain to terrified parents and students what was happening.

A new wave of chemical attacks began after the new year holidays in late March.

Thousands of students have been affected, mostly girls, with hundreds hospitalized and symptoms including respiratory distress, numbness in their limbs, heart palpitations, headaches, nausea, and vomiting.

Iran's student movement gained momentum last year amid the "Woman, Life, Freedom" protests following the death in custody of Mahsa Amini. Universities were the scene of large anti-regime demonstrations.

According to the US-based Human Rights Activists News Agency (HRANA), 637 students from 144 universities have been arrested since mid-September.

Some sources inside Iran have also announced that the number of detained students is more than 700.