U.S. Secretary of Defense Leon Panetta has called for an independent review looking into the handling of remains at the Air Force mortuary affairs operations at Dover Air Force Base.

Panetta's call comes after U.S. Air Force investigators found, according to the Office of Special Counsel, "serious misconduct" in the handling of remains of the nation's war dead at Dover.

A Pentagon official said this week that among the findings were several instances in which portions of remains from troops killed in action were lost or unaccounted for.

Panetta's move also comes after the Washington Post reported that the ashes of cremated body parts from some of the war dead were dumped in landfills until 2008, unbeknownst to their survivors.

Air Force Chief of Public Affairs Brig. Gen. Les Kodlick acknowledged the former practice on Wednesday. He said remains from cremated body parts now are disposed of at sea.

Kodlick issued a statement describing instances prior to 2008 when families had authorized portions of remains to be disposed of. An Air Force official speaking on background emphasized that families had authorized disposal of those remains, but did not know the ashes would be put in a landfill.

Military escorts accompanied the remains to a crematorium near Dover Air Force Base Mortuary, which processes remains of service members killed overseas, the statement said.

After cremation, the ashes were escorted back to Dover, Kodlick said, and then turned over to a contractor "for further incineration and disposition in accordance with medical disposition."

"The common practice was that any residual matter remaining after incineration was disposed of by the contractor in a landfill," Kodlick said.

"We could have done it better," he said.

The Air Force official speaking on background emphasized that these situations did not involve bodies but "parts of bone and other DNA material."