A single suicide bomber carried out an attack last year outside Kabul's airport that killed at least 173 people, including 13 U.S. soldiers, a Pentagon investigation has concluded.
The investigation released on February 4 ruled out more than one perpetrator and the use of firearms in the August 26 attack, which was claimed by the Islamic State Khorasan (IS-K) group.
The bombing occurred during the final chaotic days of the withdrawal of the U.S.-led military coalition from Afghanistan.
The bomb exploded outside one of the airport gates as thousands of people pushed to try to get inside the airport's perimeter.
The report said gunfire that erupted after the bombing was warning shots and none of the people killed was hit by it.
"There were no gunshot wounds" among the victims, said Brigadier General Lance Curtis, who presented the investigation’s findings.
Curtis admitted that the U.S. military initially thought the attack involved gunman as well as the bomber.
"We now know that the explosive fired ball bearings, causing wounds that looked like gunshots. When combined with a small number of warning shots, that led many to assume that a complex attack had occurred," Curtis said.
Adding to the confusion was that the shrapnel from the bomb punctured tear-gas canisters carried by the U.S. troops for crowd control.
The perpetrator, shown in the investigators' sole video of the bombing, was later identified by IS-K as Abdul Rahman al-Logari, who was released from prison by the Taliban after the militant group took control of Kabul 11 days before the bombing.