WASHINGTON — A tragic missile strike targeting an elementary school in Iran has resulted in the deaths of over 165 people, predominantly children, due to outdated intelligence, according to a U.S. official and another source familiar with a preliminary U.S. military investigation.

This devastating incident has become a significant point of contention in the ongoing conflict, potentially marking one of the most severe civilian casualty events attributed to U.S. military operations in the past 20 years, should it be confirmed as a U.S. action.

Initially, President Donald Trump pointed fingers at Iran for the attack. However, he later expressed uncertainty about the responsible party and committed to accepting the Pentagon’s investigative findings. The situation gained further attention after the New York Times revealed that preliminary evidence suggested U.S. involvement.

U.S. Central Command is reported to have executed the missile strike based on outdated target coordinates obtained from the Defense Intelligence Agency, according to sources familiar with the findings.

The Defense Intelligence Agency has not responded to requests for comment on the matter.

The agency did not respond to a request for comment.

The preliminary finding prompted immediate calls for more information from the Pentagon. White House press secretary Karoline Leavitt said that “the investigation is still ongoing.”

Both the U.S. official and the person familiar with the matter spoke to The Associated Press on the condition of anonymity to discuss the sensitive matter.

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 the strike.

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.

“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.

The revelation could 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 pointing to US responsibility for strike

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.

Publicly available satellite imagery shows the school building was part of the military compound until about 2017, when a new wall was added to separate the two. A watchtower on the property was also removed. Around the same time, the imagery shows the walls surrounding the building were painted with murals in vibrant colors, primarily blue and pink, so bright they’re visible from space

The school was clearly labeled as such in online maps and has an easily-accessible website full of information about students, teachers and administrators.

International law governing warfare bars strikes on structures, vehicles and people that are not military objectives and combatants. Civilian homes, schools, medical facilities and cultural sites are generally off limits for military strikes. The proximity of a school to a valid military target does not change its status as a civilian site, said Elise Baker, a senior staff lawyer at the Atlantic Council, a Washington-based nonprofit think tank.

If the U.S. is found responsible, said Sen. Tim Kaine during a briefing with journalists on Wednesday: “It’s either we’ve changed our traditional targeting rules or we made a mistake.”

“If we’ve changed our traditional targeting rules and we no longer provide the same level of protection for civilians, that would be tragic,” Kaine said.

Some Republicans, too, are sounding alarms.

Sen. Kevin Cramer of North Dakota told reporters that an investigation needs to “get to the bottom of it,” and then “admit if you know whose fault it is.”

If the U.S. was behind it, Cramer said, the military must “do everything you can to eliminate those mistakes going forward.”

He added: “But you also can’t undo it.”

Guardrails to curb civilian deaths have been gutted

Congress directed the Pentagon to create the Civilian Protection Center of Excellence in late 2022 as part of the wide-ranging annual defense authorization bill, which passed both chambers with broad bipartisan support. The bill said the center was to “institutionalize and advance knowledge, practices, and tools for preventing, mitigating, and responding to civilian harm.”

The measure put into law an initiative that had already been started by Defense Secretary Lloyd Austin earlier that year. The 36-step action plan was “ambitious and necessary,” Austin said at the time.

In April 2023, that office had a full-time director hired by the Army and an initial core staff of 30 civilians, according to a 2024 Pentagon report that said that the workforce was expected to grow.

Wes Bryant began working there in 2024 as the Branch Chief of Civil Harm Assessments. One of the things the office was discussing was updating the “no strike list,” he said, a series of civilian targets in other countries that the Pentagon keeps. When he was working at the Pentagon, it was well known that the list was out-of-date, he said. But under Hegseth, the office’s size was slashed and the work on updating the no-strike lists stopped, he said.

“They have no budget. They’re just sitting there trying to maintain any semblance of the mission,” he said.

Capt. Tim Hawkins, the spokesman for U.S. Central Command, denied reports that the military command only had a single person assigned to the mission but would not offer any further details, citing the ongoing investigation.