Two of four purported American marines, seen in a video that appears to show them urinating on the dead bodies of Afghan Taliban fighters, are said to have been identified.
A Marine Corps official, speaking on condition of anonymity, also said the images were believed to be authentic.
The US has condemned the footage – posted on the internet – and ordered an immediate investigation.
“I want to express my total dismay at the story concerning our marines, who I have the highest respect and admiration for, but I share completely the views expressed by Defence Secretary Leon Panetta earlier today. I join him in condemning the deplorable behaviour that is reflected in this video,” said Hillary Clinton, US Secretary of State.
The news has been widely broadcast by media in Afghanistan and is likely to stir-up already strong anti-US sentiment.
“If these actions continue, people will not like them (Americans) any more and there will be an uprising against them,” said one Kabul resident.
The images have come to light at a particularly sensitive time, when the US is trying to foster peace talks between the Afghan government and the Taliban.
Afghan President Hamid Karzai has called on the US military to punish those involved for their “inhuman” actions.