At least two of the four U.S. marines captured in an Internet video that appears to show them urinating on Taliban corpses in Afghanistan have been identified, an official said Thursday.

A Marine Corps official said the four were members of the 3rd Battalion, 2nd Marines, which returned to its home base in North Carolina last fall after a tour in Afghanistan, CBS News reported. As a criminal investigation is now under way, the official spoke on condition of anonymity.

Some of the four Marines are no longer in the battalion, the official said without providing any further details.

On Thursday, Defense Secretary Leon Panetta condemned the actions in the video.

I condemn it in the strongest possible terms, Panetta said. This conduct is entirely inappropriate for members of the United States military and does not reflect the standards or values our armed forces are sworn to uphold. Those found to have engaged in such conduct will be held accountable to the fullest extent.

The Marine Corps said it would investigate the YouTube video, but had not yet verified its origin or authenticity. The case has been referred to the Naval Criminal Investigative Service, the Navy's worldwide law enforcement arm. It is unclear where the video originated.

Spokesman Jay Carney said the White House won't pass judgment until the details are discovered, as it is now a legal matter, but that the apparent activity is deplorable and regrettable.

In the video, four men in Marine uniforms and combat gear are shown exposing their genitals and urinating on three dead bodies. One of the deceased has a large blood stain on his chest, Fox News reported.

The reaction from Afghanistan was one of fury.

The government of Afghanistan is deeply disturbed by a video that shows American soldiers desecrating dead bodies of three Afghans, President Hamid Karzai said in a statement from the president's office Thursday.

This act by American soldiers is simply inhumane and condemnable in the strongest possible terms. We expressly ask the U.S. government to urgently investigate the video and apply the most severe punishment to anyone found guilty in this crime.

Of greater concern now is how (and if) the video will affect potential peace talks among the U.S., Karzai and the Taliban, though a senior spokesman for the militant group maintained that it would not complicate plans for peace negotiations.

This is yet another barbaric act by foreign forces. Over the past 10 years, there have been hundreds of similar cases that were not revealed, said Zabihullah Mujahed of the Taliban in a statement. I don't think this new issue will affect negotiations, which, at this stage, are mainly about prisoner exchange.

Marines Corps Commandant James F. Amos said Thursday that he viewed the video apparently showing Marines desecrating the bodies of several dead Taliban in Afghanistan and requested the Naval Criminal Investigative Service pull together a team of their very best agents to investigate every aspect of the filmed event.

I want to be clear and unambiguous, the behavior depicted in the video is wholly inconsistent with the high standards of conduct and warrior ethos that we have demonstrated throughout our history, the general said.

Rest assured that the institution of the Marine Corps will not rest until the allegations and the events surrounding them have been resolved. We remain fully committed to upholding the Geneva Convention, the laws of war and our own core values.