Taliban fighters entered Kabul airport last week and drove Afghan civilians away from the runway following a breach in the US military’s perimeter, three US defense officials told Al-Monitor.

The Taliban's move came after thousands of panicked Afghans flooded onto the tarmac Aug. 16 from the southern side of the airport, home to the main commercial air terminal. The chaos on the runway forced the US military to temporarily halt ongoing evacuation flights and led to several civilian deaths. It also triggered an investigation by the US Air Force.

While some events leading up to the breach remained unclear, officials told Al-Monitor that the commercial terminal on the south side of the airport had not been fully secured by arriving US troops. Instead, US military commanders deploying forces to the airport had believed US-trained Afghan national security forces were guarding that side of the facility.

The Taliban’s role in clearing the airfield, which has not been publicly acknowledged by Pentagon officials, underscores the haste with which the Biden administration deployed troops to Kabul airport in response to the unexpected speed at which the insurgents swept to power in Afghanistan.