The White House also expressed regret for the latest in a string of embarrassing missteps by the U.S. military in a decade-old war whose strategy is built upon efforts to earn the trust and confidence of ordinary Afghans. In recent months American troops have been caught up in controversies over the burning of Muslim holy books, urinating on Afghan corpses, an alleged massacre of 17 Afghan villagers and other misdeeds.

``My apology is on behalf of the Department of Defense and the U.S. government,'' Panetta told a news conference in Brussels following a meeting of NATO allies where the way ahead in Afghanistan was the central topic.

The photos were published in Wednesday's Los Angeles Times. One shows members of the 82nd Airborne Division posing in 2010 with Afghan police and the severed legs of a suicide bomber. The same platoon a few months later was sent to investigate the remains of three insurgents reported to have accidentally blown themselves up _ and soldiers again posed and mugged for photo with the remains, the newspaper said.

A photo from the second incident appears to show the hand of a dead insurgent resting on a U.S. soldier's shoulder as the soldier smiles.

The 82nd Airborne confirmed that the soldiers are members of the 1st battalion, 508th Parachute Infantry Regiment, 4th Brigade. The brigade returned from a year-long deployment to Afghanistan in August 2010. The 82nd Airborne referred questions about the matter to the Pentagon.

An Army spokesman, George Wright, said, ``We do not condone service members engaging in such behavior or possessing related materials. This matter remains under investigation by the unit.''

The colonel who commanded the brigade in Afghanistan, Brian Drinkwine, did not respond to an email request for comment. The brigade's Facebook page includes an account of the September 2010 ceremony at Fort Bragg in which Drinkwine relinquished command, quoting him as praising his soldiers' efforts and professionalism.

``The Taliban feared you, the people trusted you and your Afghan partners respected you and you inspired them,'' he is quoted as saying.

Gen. John Allen, the top commander of U.S. and all international forces in Afghanistan, issued a statement condemning the photos. He said they represented a violation of a policy for the handling of enemy remains and it dictates they be processed as humanely as possible.

``The incident depicted in the LA Times' photographs represents a serious error in judgment by several soldiers who have acted out of ignorance and unfamiliarity with U.S. Army values,'' Allen said, adding that commanders ``will collaborate with Afghan authorities and carefully examine the facts and circumstances shown in these photos.''

President Barack Obama's chief spokesman, Jay Carney, called the early February 2010 incident was ``reprehensible.''

Carney said the picture-taking incident does not represent the standards of the U.S. military and said that Obama believes the situation needs to be investigated and those responsible held accountable. He said he didn't know if the president had seen the photos.

Top U.S. military and civilian officials rushed to condemn the soldiers' actions Wednesday, calling them repugnant and a dishonor to others who have served in the conflict. The Army said an investigation is under way.

Panetta said he condemned the behavior, but said, ``This is war. I know that war is ugly and it's violent, and I know that young people sometimes caught up in the moment sometimes make very foolish decisions.''

The U.S. military image in Afghanistan has been taking a beating in recent months. In January, U.S. Marines were found to have made a video of themselves urinating on Afghan corpses. In February, what the military said was the accidental burning of Qurans triggered violent protests and revenge killings of six Americans. And last month, a U.S. soldier left his base and allegedly killed 17 civilian villagers, mainly women and children.

The Times said that a soldier provided the newspaper with a series of 18 photos of soldiers posing with corpses. The soldier served in Afghanistan with the 82nd Airborne's 4th Brigade Combat Team from Ft. Bragg, North Carolina, and said the photos point to a breakdown in leadership and discipline that he believed compromised the safety of the troops, the newspaper reported.

Even before the photos were published online, Pentagon press secretary George Little said Panetta ``rejects the conduct depicted in these two-year-old photographs.''

``Anyone found responsible for this inhuman conduct will be held accountable in accordance with our military justice system,'' Little said.

The U.S. commander of NATO forces in Afghanistan, Marine Gen. John R. Allen, also criticized the troops

A statement by U.S. Ambassador to Afghanistan Ryan C. Crocker and White House spokesman Jay Carney also condemned the behavior.

``Such actions are morally repugnant, dishonor the sacrifices of hundreds of thousands of U.S. soldiers and civilians who have served with distinction in Afghanistan, and do not represent the core values of the United States or our military,'' Crocker said.

Little said the military had asked the Los Angeles Times not to publish the photographs. ``The danger is that this material could be used by the enemy to incite violence against U.S. and Afghan service members in Afghanistan,'' he said.

There was no immediate reaction from Afghan authorities.

In its story, the newspaper quoted editor Davan Maharaj saying: ``After careful consideration, we decided that publishing a small but representative selection of the photos would fulfill our obligation to readers to report vigorously and impartially on all aspects of the American mission in Afghanistan, including the allegation that the images reflect a breakdown in unit discipline that was endangering U.S. troops.''

Many troops take photos _ and some take these `trophy' photos _ of their tours of duty on the battlefield. And the practice has harmed war efforts in both recent campaigns in Iraq and Afghanistan.

The most notorious case was that of Abu Ghraib, an Iraq prison where members of the Maryland-based 372nd Military Police Company photographed themselves physically and sexually abusing detainees. Photos showed them holding one prisoner on a dog leash, another with a prisoner hooded and wires attached to him in a mock electrocution, another with naked prisoners stacked in a pyramid.

Release of the photos in 2004 fostered international condemnation. It complicated international relations for the U.S. and provoked debate about whether harsh interrogation techniques approved by the Pentagon amounted to torture.  In all, eleven U.S. soldiers were tried and convicted of crimes and five others were punished administratively. Punishments for the 16 included reprimands, hard labor, demotions, fines and up to 10 years in prison for one soldier.

In the more recent incident _ the video of Marines urinating on Afghan corpses _ two separate investigations have been completed and are being reviewed by the commander of Marine Corps Combat Development Command, Lt. Gen. Richard Mills. One investigation was done by the Naval Criminal Investigative Service to determine whether any crime was committed; the other was a command probe aimed at determining what happened and why. No action has been taken against the Marines pending the review of the investigations, according to Marine Corps officials. (AP)