The families of more than a hundred children killed when a missile struck an elementary school in Iran have penned a letter of grief and gratitude to Pope Leo XIV, who has repeatedly criticized the loss of innocent lives in the war with Iran.

An investigation by the U.S. military determined that the United States was responsible for the Tomahawk missile that destroyed the Shajarah Tayyebeh elementary school in the town of Minab, on Feb. 28, the first day of the war, killing 175 people, according to the preliminary findings of the inquiry.

The authors of the letter, which was published by Iranian state media on April 19, called themselves “the fathers and mothers of 168 children who, these days, instead of hugging the warm bodies of our children, are clutching their burned bags and bloody notebooks to our chests.”

The letter thanked the pontiff for being the “the voice for our voiceless children,” and then urged him to keep promoting peace and dialogue in the hope that no other parent would have to suffer the loss of a child in the fighting.

“Our children will never return home to build a brighter future, but it is the prayer of us grieving parents that your message to lay down the weapons be heard, at a time when the United States and the Israeli regime fuel the flames of these atrocities with their excessive demands,” the authors wrote, according to Iranian state media.

On Thursday, during his flight back to Rome after an 11-day trip to Africa, Leo said that he had seen the letter and used it to call attention to the loss of innocent lives in the conflict. At least 1,665 civilians had been killed in Iran, according to the Human Rights Activists News Agency.

The families “speak about how they have lost their children, who died in that event,” the pope said to reporters, referring to the airstrike on the school. “The issue is not whether there is regime change or not; the issue is how to promote the values we believe in without the death of so many innocent people.”

On Saturday, President Trump called off a trip by two of his top negotiators, who had planned to travel to Pakistan for peace talks. Iran and the United States have been locked in a stalemate over the Strait of Hormuz, where both sides are blockading ships, as a truce between Israel and Lebanon has been teetering because of clashes between Israel and Hezbollah, an Iran-backed militia.

“We do not know where things are heading,” Leo said on Thursday, referring to the on-again-off-again peace talks. “This chaotic, critical situation for the global economy has been created, but there is also an entire population in Iran of innocent people suffering because of this war.”

The American-born pontiff has been one of the world’s most powerful and vocal critics of the war, angering President Trump, who has called Leo “weak on crime” and “terrible for foreign policy.” Vice President JD Vance, who is a Catholic, also waded into the theological fight, attempting to justify the U.S. and Israeli military campaign in Iran as a just cause.

Mr. Trump has tried to sidestep blame for civilian deaths in Iran and other places touched by the war. At one point, before the preliminary results of the military inquiry became public, the president even briefly blamed Iran for the strike on the elementary school.

The American investigation said the strike stemmed from a targeting mistake by the U.S. military, which was conducting attacks on an adjacent base operated by the Islamic Revolutionary Guards Corps, according to the preliminary findings. Officers used outdated data when they were planning strikes on an adjacent Iranian military base, and the school building had once been part of the base, the preliminary investigation found.