WASHINGTON, DC -- U.S. Defense Secretary Leon Panetta ordered the Air Force to take a second look at punishment doled out over the mishandling of the remains of war dead, including losing track of body parts.

The announcement came the day that Air Force Chief of Staff General Norton Schwartz braved a Senate hearing where he defended the decision not to fire anyone.

One military officer and two civilians received disciplinary action, steps the U.S. Office of Special Counsel said in a letter this week to President Barack Obama did not go far enough.

"I want to make certain that we have taken all appropriate disciplinary action here," Panetta told reporters at the Pentagon, adding he trusted the Air Force secretary to do an honest review, despite scathing criticism of the Air Force's investigation by the OSC.

"I consider (Dover) a sacred place with a sacred responsibility. And it is a place that must meet the highest standards for caring for the remains of our fallen heroes."

The Dover Air Force base in Delaware is the main entry point for returning American war dead from the conflicts in Iraq and Afghanistan.

Schwartz appeared to downplay the severity of the actions by Dover mortuary personnel, describing them as unintentional mistakes at a Senate hearing.

"Clearly (there) were unacceptable mistakes made. Whether they constitute wrongdoing is another matter entirely," Schwartz told the hearing, called to discuss an unrelated matter involving the U.S. National Guard.

The revelations about Dover have come in two stages this week, as Americans prepare to honor Veterans Day on Friday.

The first came with the disclosure on Tuesday of a U.S. investigation that the Dover mortuary lost track of body parts twice and even wrongfully removed a limb of a Marine. The OSC said the Air Force took too long to notify families and warned of alleged retaliation against whistle-blowers.

Schwartz addressed another controversial practice, since abandoned, at Thursday's hearing: body parts of war dead had been cremated, incinerated and then dumped in a landfill until 2008. That happened in cases where residual remains were found after families received the bodies of their loved ones.

An Air Force official, speaking on condition of anonymity, told Reuters that families had granted the military authorization to deal with any residual remains, but acknowledged they had not been made aware those remains would end up in a landfill.

THROWN IN THE TRASH

"I'm deeply troubled by the reports about what's happened at the mortuary at the Dover Air Force Base. And I'm sure you would agree with me, this is outrageous that remains of our soldiers would be put in a landfill," said Senator Kelly Ayotte.

The Washington Post, which first reported those details, quoted one widow saying she was "appalled and disgusted" to learn what happened to her husband's remains in a letter from the Air Force earlier this year. He died in Iraq in 2006.

"My only peace of mind in losing my husband was that he was taken to Dover and that he was handled with dignity, love, respect and honor," Gari-Lynn Smith told the Post. "That was completely shattered for me when I was told that he was thrown in the trash."

Schwartz said residual remains had been buried at sea, according to military custom, since 2008.

The revelations at Dover are likely to add to questions about treatment of America's fallen troops a year after a scandal broke at Arlington National Cemetery over the misidentification of remains.

"What happened at Arlington, nobody was intentionally mismarking graves," Senator Claire McCaskill said as she called for greater accountability in the incidents at Dover as well as an independent probe of the Air Force's own investigation.

Panetta earlier this week also announced an independent review of overall operations at the Dover Port Mortuary, which will be led by former U.S. Surgeon General Dr. Richard Carmona.