A United Nations panel of experts said on Wednesday it was "deeply disturbed" by the deaths of children, after the bombing of the Shajareh Tayyebeh girls' school in southern Iran, which it said killed more than 160 children, citing reports.
The school in Minab was hit on Saturday, the first day of US and Israeli attacks on Iran.
US Secretary of State Marco Rubio said on Monday that the country's forces "would not deliberately target a school".
Israel has said it is investigating the incident.
"The Committee is alarmed by reports of strikes on civilian infrastructure, including schools and hospitals, which have injured and traumatised children, and claimed many young lives," the UN Committee on the Rights of the Child said in a statement.
Children must be protected from war, the committee added.
The UN Committee on the Rights of the Child is a body of 18 independent experts that monitors implementation of the Convention on the Rights of the Child, which protects children’s rights to education and safeguards them from violence.
On Tuesday, the UN human rights office urged what it called "the forces behind a deadly attack on a girls' school in Iran" to investigate and share insights into the incident, without saying who it believed was responsible.
Iran's ambassador to the United Nations in Geneva, Ali Bahreini, had raised the issue with UN human rights chief Volker Turk in a March 1 letter, calling the attack "unjustifiable" and "criminal".

Sydney Airport flights disrupted due to air traffic controller shortage
Philippine firefighters enter charred ferry as search continues for dozens missing
More US lawmakers seek AI rules after Anthropic researchers warn of extinction
Fire in rebel-held east Congo kills 24 schoolchildren
Trump says he does not regret Iran war despite potential impact on elections
Trump touts $5,000 payout if Republicans win as Vance waits in wings
Search expands after Philippine ferry fire kills five and leaves dozens missing
Trump says Iran war to end after US midterm elections
