Single suicide bomber responsible for Kabul airport massacre, Pentagon says

WASHINGTON – The Pentagon's months-long investigation into the ISIS-K terror attack in Kabul in August that killed 13 U.S. troops and at least 170 Afghans found that a single suicide bomber whose explosive vest was packed with ball bearings was responsible for the carnage.

The suicide bomber killed the Afghans who had clustered near one of the entrances to Hamid Karzai International Airport and the U.S. troops screening them. The attack on Aug. 26 was one of the darkest chapters of the chaotic withdrawal of American military and diplomatic personnel after 20 years of war in Afghanistan.

The bomb contained 20-pounds of military-grade explosives and five millimeter ball bearings. The blast wounded 45 more U.S. troops, including some who suffered traumatic brain injuries.

The investigation's finding differed from initial reports that indicated there was more than one attacker, according Marine Gen. Kenneth McKenzie, commander of U.S. Central Command.

"The best information we had in the immediate aftermath of the attack indicated it was a complex attack by both a suicide bomber and an ISIS-K gunman," McKenzie said. "We now know that the explosively fired ball bearings that caused wounds that look like gunshots."

Investigators found that military leaders in Kabul had acted appropriately to protect U.S. forces, and medical personnel "saved every life they possibly could through heroic efforts," McKenzie said. "This was a terrible attack that resulted in tragic outcomes and a horrific loss of life, both Afghan and American."

More: Dire warnings, then explosions and US deaths: How a terror strike unfolded at Kabul airport

Warning shots fired by U.S. and allied troops after the attack did not wound any friendly forces or Afghan civilians, the investigation found.

"The fact that this investigation contradicted our first impression demonstrates to me that the team would enter this investigation with an open mind in search of the truth," McKenzie said. "It also confirmed the age-old fact that the battlefield is a confusing and contradictory place and it gets more confusing the closer you are to the actual action."

In the several days leading up to Aug. 26, U.S. intelligence reports indicated that ISIS-K sought to attack Afghans seeking to leave the country and U.S. troops guarding entrances to the airport. U.S. troops cooperated with Taliban militants who helped screen throngs of people streaming to the airport.

On Aug. 29, three days after the airport attack, U.S. forces launched a drone attack near the airport that killed 10 innocent Afghans. That attack was deemed an "honest mistake" by a separate Pentagon investigation. The airstrike was launched by U.S. troops who mistakenly identified the civilian vehicle as an "imminent threat."

This article originally appeared on USA TODAY: Kabul airport massacre mounted by single ISIS-K suicide bomber