U.S. President Donald Trump said on Wednesday that it may never be known who was responsible for a February 28 airstrike that killed more than 175 children and teachers at a girls’ school in Minab, southern Iran, despite an initial internal military report pointing to American forces. Speaking to reporters, Trump cast doubt on U.S. involvement, saying, “Somebody said it was our missile, maybe it wasn't our missile but I have seen nothing to lead me to believe it was,” and adding, “I don’t think it was us.”

The attack, which occurred on the first day of the U.S.-Israeli military assault on Iran, sparked global condemnation and intensified claims of war crimes. Reuters reported in March that a preliminary Pentagon investigation had found U.S. forces were likely behind the strike, possibly because of outdated targeting data. The probe has since been elevated, but the Pentagon has not publicly acknowledged any preliminary findings.

Trump declined to accept that version of events, saying, “I don’t think it was us.” He added that the fog of war made it difficult to assign blame: “There were missiles flying all over the place, and it’s horrible what happened but there were missiles flying all over the place.” The president initially claimed without evidence that Iran itself was responsible, and later said he would accept the results of the ongoing inquiry.

The school strike has become a flashpoint in debates over accountability for civilian casualties inflicted by powerful militaries. The U.N. human rights office described it as “absolutely horrific,” and legal experts say deliberately targeting a school would constitute a war crime.

Iranian officials say more than 175 children and teachers were killed. The White House has insisted that American forces would never deliberately target a school, but Trump’s remarks signal a reluctance to concede U.S. culpability even as internal military assessments suggested otherwise.