The Pentagon is calling an August 29 drone strike that killed up to 10 civilians in Afghanistan, including seven children, a tragic mistake.

The strike was meant to target the masterminds of an earlier attack on the Kabul airport, which was blamed on ISIS-K. And for weeks, the Pentagon maintained that despite the inadvertent deaths of civilians, the mission had been successful.

But on Friday, officials said an internal review revealed that no Islamic State members had been killed in the attack, only civilians.

"The strike was a tragic mistake," Marine Gen. Frank McKenzie, head of US Central Command, told a Pentagon news conference.

"I am now convinced that as many as 10 civilians, including up to seven children, were tragically killed in that strike," McKenzie added. "Moreover, we now assess that it is unlikely that the vehicle and those who died were associated with ISIS-K or a direct threat to U.S. forces."The retaliatory strike came amid the massive evacuation effort in Afghanistan and three days after more than 150 people were killed by a suicide bomber outside of one of the airport gates, including 13 U.S. troops.