Alerts that toxic substances were being spread in school environments in Iran came in November, and since then more than 5,000 schoolgirls in the country have suffered from symptoms such as shortness of breath and nausea.
Protests have since flared up and worried parents have, among other things, protested outside the Ministry of Education in the capital Tehran.
They believe that the whole thing is a revenge campaign after girls demanded more freedom.
- With the help of tip-off information, a number of people have been arrested in five provinces, and the relevant authorities are investigating this fully, says Majid Mirahmadi, a high-ranking official at the Ministry of the Interior, on state television.