The Associated Press / Rescue workers and residents search through the rubble in the aftermath of a strike on a girls’ elementary school in Minab, Iran, on Feb. 28.

WASHINGTON — Dozens of Democratic senators demanded answers from the Trump administration on Wednesday as a growing body of evidence suggested that the U.S. was likely responsible for a strike at an elementary school in Iran that killed over 165 people, many of them children.

The letter from more than 45 senators pressed Defense Secretary Pete Hegseth on whether the U.S. was culpable for the strike and what previous analysis of the building had been done. The senators also raised concerns about the Pentagon hollowing-out a congressionally mandated office set up specifically to reduce civilian casualties.

The bombing of the school and the casualties involving children have become a focal point of the war, and if confirmed to be at the hands of the U.S., would also stand among the highest civilian casualty events caused by the American military operations in the last two decades.

President Donald Trump initially blamed Iran for the attack, later said he wasn’t certain who was to blame, and then said he would accept the results of the Pentagon’s investigation. The issue took on added urgency on Wednesday after the New York Times reported that a preliminary investigation found that the U.S. was responsible.

“Under this administration, budgetary and personnel cuts at the Department have robbed military commands of crucial resources to prevent and respond to civilian casualties,” the senators wrote. Those include cuts at U.S. Central Command, whose forces are leading the military campaign against Iran, and the Civilian Protection Center of Excellence, which was signed into law in 2022 as part of a Pentagon ambition to reduce death tolls from strikes.

If the U.S. is determined to be responsible, the revelation would threaten to erode public support in the U.S. effort against Iran at a time when Trump, who as a candidate railed against American involvement in “stupid” overseas wars, faces persistent questions about the purpose and of the conflict and what would bring it to an end.

One former Pentagon official said the Feb. 28 strike that hit Shajareh Tayyebeh Elementary School, which is located near a neighboring base for the Iranian Revolutionary Guard, came as a natural result of changes made by the Trump administration to reduce staff to mitigate civilian harm and Hegseth’s emphasis on lethality over legality.

Evidence mounts of US responsibility

There are several indications that the strike on the school may have been avoidable.

It happened Saturday morning, the start of the Iranian school week, when the building was full of young children. Satellite analysis by the AP shows that the school, as well as other targets struck the same day, had characteristics visible from the air that could have identified them as civilian sites before they were struck.

The AP reported last week that satellite images, expert analysis, a U.S. official and public information released by the U.S. military all suggested it was likely a U.S. strike. That evidence grew stronger on Monday, as new footage emerged showing what experts identified as a U.S.-made Tomahawk cruise missile slamming into the military compound as smoke was already rising from the area where the school was located.