US secretary of state Hillary Clinton described the marines' behaviour as 'deplorable' Reuters

Four US marines identified by the military as the soldiers filmed urinating on corpses in Afghanistan are likely to face a court martial after an American military commander said such actions are a "grave breach" of the laws of war.

The Naval Criminal Investigation Service (NCIS) has interviewed two of the soldiers featured in the video laughing and making snide remarks as they urinated on the bloodied bodies of three Afghan men, who have not been identified. It is not clear if the men were members of the Taliban.

In attempt to dampen the growing diplomatic storm around the abuse, the commanders of US forces in Afghanistan on Friday ordered American troops to treat the bodies of killed enemies and civilians with "appropriate dignity and respect".

The soldiers were members of a sniper unit that completed a six-month tour of duty in Afghanistan's Helmund province in September and returned to Camp LeJuene in North Carolina where the video was passed around. The two others are believed to have left the military.

The nature of the charges are unclear although desecrating bodies is a crime under US military law and the Geneva conventions.

The deputy commander of US forces in Afghanistan, lieutenant general Curtis Scaparrotti, said in a message to troops on Friday that "defiling, desecrating, mocking, photographing or filming for personal use insurgent dead constitutes a grave breach" of laws governing armed conflict. He said it also violates "basic standards of human decency, and can cause serious damage to relations with the Afghan government".

The US secretary of state, Hillary Clinton, said she believed the men may be guilty of a war crime.

"Anyone, anyone found to have participated or know about it, having engaged in such conduct, must be held fully accountable," she said.

In the 39-second video, the four soldiers in combat gear and carrying weapons are seen acting in unison as they stand over the corpses and urinate. They sigh and laugh. One of the marines says "Have a great day, buddy" while another comments "Golden, like a shower".

They are clearly not concerned at being caught. One of them asks a fifth soldier who is filming the incident: "You got it on the video?"

It is not publicly known who posted the footage of the incident on the web, which prompted a wave of denunciations.

The Afghan president, Hamid Karzai, called the soldiers' actions "inhumane" and the US defence secretary, Leon Panetta, said that after watching the video he found it "utterly deplorable".

But the actions of the soldiers were not met with universal disapproval. A prominent anti-Muslim activist in New York, Pamela Geller, who was at the forefront of the campaign against an Islamic centre near ground zero and has been embraced by some mainstream Republicans including Newt Gingrich, praised the soldiers for desecrating the Afghan corpses who she called "murderous savages".

"I love these marines. Perhaps this is the infidel interpretation of the Islamic ritual of washing and preparing the body for burial," she wrote on her blog, Atlas Shrugs.

Geller leads two groups, the Freedom Defence Initiative (FDI) and Stop Islamisation of America (SIOA) that have become increasingly influential as conservative politicians seek to exploit anti-Muslim sentiment in the US.

The marine corps has launched its own inquiry led by a general and a senior lawyer.

"Rest assured that the institution of the marine corps will not rest until the allegations and the events surrounding them have been resolved," said the corps' commander, general James Amos.