A student on Wednesday threw a tear gas canister in a schoolyard in Tanta in Gharbiya Governorate, causing 50 students to be hospitalized.
The students were taken to Tanta University Hospital for treatment and were expected to be released within a few hours.
In Minya on Monday, two young men reportedly deployed a tear gas canister onto a city street, making it difficult to breathe for dozens of people.
The police arrested two suspects, age 21 and 22, and said they confessed during interrogations to buying the tear gas from Central Security Forces conscripts.
The noxious gas is typically used as a protest control measure by security forces.
Edited translation from Al-Masry Al-Youm