Washington: The US Army on Monday formally apologised "for the distress" caused by pictures portraying abuse allegedly committed by US troops serving in Afghanistan.
"We apologize for the distress these photos cause," said a statement released by the Army.
German weekly Der Spiegel earlier Monday published photos that it said showed two US soldiers in Afghanistan from a rogue army unit posing with dead Afghans.
Two photos, which Spiegel said US authorities had sought to keep secret, appear to show two members of a unit that allegedly killed Afghan civilians for sport.
In one, a purported soldier, cigarette in hand, holds up the head of a blood-spattered man who is apparently dead. In a second, another purported soldier is grinning widely while also holding up the same man.
A third photo shows two bodies propped up against a post. Again the people in the picture appear to be dead.
The Army statement said the actions seen in the pictures were "repugnant to us as human beings and contrary to the standards and values of the United States Army."
It noted that the actions portrayed in these photographs were under investigation and subject to ongoing US court-martial proceedings.
"These court-martial proceedings speak for themselves," the Army said. "The photos appear in stark contrast to the discipline, professionalism and respect that have characterized our soldiers` performance during nearly 10 years of sustained operations."
The photos relate to an ongoing high-profile case of soldiers accused of killing civilians, mutilating their bodies and collecting trophies.
Spiegel said one of the troops in the photos is Corporal Jeremy Morlock, who faces charges of premeditated murder in the deaths of three Afghans.
The other, Private Andrew Holmes, stands accused of participating in a plot to execute an Afghan man in January, the magazine said.
The plan, supposedly concocted by ringleader Sergeant Calvin Gibbs and Morlock, allegedly involved shooting a civilian and tossing a Russian-made grenade at the man to make it appear he was an enemy combatant.
In November, Holmes won a temporary reprieve from legal action relating to murder charges, according to his lawyer.
Morlock is one of five soldiers charged with murder in the case, while seven others are accused of trying to block the investigation, using hashish and severely beating a comrade in retaliation for informing superiors.
Spiegel said the US military tried to prevent the publication of the pictures, fearing a possible backlash against its troops on the ground in Afghanistan.
The well-respected magazine said it had researched the story of the so-called "Kill Team" for five months.
"Spiegel is publishing only three of the 4,000 pictures and videos, only those which are necessary for the story which needs to be told here," the magazine said.