WASHINGTON (AP) — The Pentagon retreated from its defense of a drone strike that killed as many as 10 civilians in Afghanistan last month, announcing Friday that an internal review revealed that only civilians were killed in the attack, not an Islamic State extremist as first believed.

For days after the Aug. 29 strike, Pentagon officials asserted that it had been conducted correctly, despite numerous civilians being killed, including children.

“Having thoroughly reviewed the findings of the investigation, and the supporting analysis of interagency partners, I am now convinced that as many as 10 civilians, including up to 7 children, were tragically killed in that strike,” Gen. Kenneth McKenzie, the top general of US Central Command, said in a statement on Friday. “Moreover, we now assess that is now unlikely that the vehicle and those who died were associated with ISIS-K, or were a direct to US forces. I offer my profound condolences to the family and friends of those who were killed. This strike was taken in the earnest believe that it would prevent an imminent threat to our forces and the evacuees at the airport. But it was a mistake, and I offer my sincere apologies. As the combatant commander, I am fully responsible for this strike and its tragic outcome.”

News organizations later raised doubts about that version of events, reporting that the driver of the targeted vehicle was a longtime employee at an American humanitarian organization and citing an absence of evidence to support the Pentagon’s assertion that the vehicle contained explosives.