The US Air Force Office of Special Investigations is opening an investigation into human remains found in the wheel well of a C-17 that took off from Kabul's international airport, the Air Force said in a statement.
The remains were discovered after the plane landed at Al Udeid Air Base in Qatar.
"The aircraft is currently impounded to provide time to collect the remains and inspect the aircraft before it is returned to flying status," the statement said.
The crew made the decision to take off because of the deteriorating security situation at the airport after hundreds of Afghans breached the perimeter and surrounded the C-17. Video of Afghans running with the plane went viral, as did video of appearing to show Afghan civilians falling from the side of the plane in mid-air after desperately trying to hold on.
Note: This is a different flight from the C-17 which was packed with 640 people on board as it flew out. That flight left Sunday night.