The attack on the Iranian primary school (not makeshift sheltered building) is on the very first day of the war, not several weeks, months or years.
Not to downgrade the incident, but the Mariupol incident you mentioned probably happened in 2022 while the all out war started in 2014 [1],[2]. If you can refer and link to the particular incident it'll be helpful for verification.
[1] Siege of Mariupol:
https://en.wikipedia.org/wiki/Siege_of_Mariupol
[2] Russo-Ukrainian war:
The theater was marked with huge inscription of "CHILDREN" on tarmac, in the pilots' native Russian. They killed them regardless.
Either way do you think that if it happened on day one instead of 3 weeks in the reaction would be any different?
After several weeks of bombardment and siege like was happened in Mariupol, children were already stop attending schools, moved to other schools, go to bunkers, live in makeshift shelters or migrate to different cities [1].
"The Geneva Conventions state that the parties to a conflict must do their best to protect civilians, which may include moving civilians and civilian objects under their control if they are close to military objectives." [1]
[1] Fact check: What do we know about the airstrike on a school in Iran?
https://www.euronews.com/my-europe/2026/03/16/fact-check-wha...
