Iran has blamed Israel and the United States for the strike on the school in the Iranian city of Minab on the first day of the war on Saturday, giving a toll of more than 150 dead.

Neither the United States nor Israel have confirmed the attack, and AFP has been unable to independently verify the toll or visit the site.

"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," it said.

"This is a reminder that children are among the most vulnerable in armed conflicts, and must never be treated as collateral damage."

According to state media, Iran on Tuesday held funerals for at least 165 people, including students, killed in the alleged strike.

State television carried images showing a large crowd of mourners in Minab weeping over what appeared to be bodies wrapped in white shrouds.

The UN committee's 18 independent experts are tasked with monitoring how countries implement the Convention on the Rights of the Child.

The convention came into force in 1990. Every United Nations member state is a party, except the United States.

The convention requires countries to safeguard the rights to life, survival and development of every child, and to take all measures to ensure children's rights are respected in armed conflicts.

"Children must be protected from direct and indirect effects of hostilities," the committee said.

It called for an immediate and sustained ceasefire by all parties to the Middle East war "so that children are no longer exposed to killing, maiming, displacement, psychological harm, or other violations of their rights".

It also urged the warring parties to take all necessary measures to protect children, including ensuring that schools and hospitals are not attacked and that humanitarians can safely reach children in need.

The committee's opinions are non-binding but carry reputational weight.