Democratic senators led by Kirsten Gillibrand called on Monday for President Donald Trump’s administration to disclose within the next week the findings from a U.S. military investigation into a Feb. 28 strike at a girls’ school in Iran.

Reuters first reported on March 5 that an initial, internal U.S. military investigation showed U.S. forces were likely responsible for the fatal strike in Minab on the opening day of the war with Iran.

The group of more than two dozen U.S. senators, including the top Democrat on the Senate Armed Services Committee, Jack Reed, requested in a letter the U.S. military finalize its investigation, brief Congress and present a plan to ensure such a mistake does not happen again.

“There is no justification for withholding an unclassified accounting of what happened, what went wrong, and what the Department is doing to prevent recurrence,” their letter said.

Asked for comment, a Pentagon official told Reuters: “The investigation is ongoing. We do not have any updates to announce at this time.”

The strike killed more than 175 children and teachers, Iranian officials say. The lawmakers’ letter notes that would make it the U.S. military’s largest civilian casualty incident since 1991, when it mistakenly bombed a shelter in Iraq, killing more than 400 civilians.

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Archived copies of the Iranian school’s official website show the school is adjacent ‌to a ⁠compound operated by the Islamic Revolutionary Guard Corps, the military force that reports to Iran’s supreme leader.

Reuters, citing sources familiar with the matter, has reported that U.S. officials responsible for creating targeting packages appeared to have used out-of-date intelligence.

U.S. Admiral Brad Cooper, head of ​Central Command, which is directing the war effort, testified in May that the investigation was “complex” given ‌that the school was located on an active Iranian cruise missile base.

Trump, however, has cast doubt on whether the U.S. military will ever know what happened given the amount of military activity at the start of the war.

“Somebody said it was our missile, maybe ​it wasn’t our missile but I have seen nothing to lead me to believe ‌it ⁠was.” Trump remarked on June 24, adding: “I don’t think it was us.”

Iranian officials have pointed to the strike on the school as a U.S. war crime. The U.S. has said it never intentionally targets civilians.

In the letter, the lawmakers ask Cooper and U.S. Defense Secretary Pete Hegseth to submit an unclassified version of the findings to Congress and the U.S. public. They also ask for a prevention and remediation plan “that identifies the specific corrective actions the Department will take to ensure this does not happen again.”

“The United States military has a legal and moral obligation to take all feasible precautions to prevent civilian harm,” the letter said.

“When a U.S. strike kills civilians, the Department owes Congress, the American people, and the victims’ families a clear accounting of what happened and a credible plan to prevent future failures.”