WASHINGTON - The US Army on Monday promised to pursue "the truth" as disturbing photos of US soldiers murdering innocent Afghan civilians were published by the Rolling Stone magazine.

The magazine released a series of gory images and videos depicting dead Afghans as well as US soldiers who posed with the bodies. One photo even showed a soldier took a stick to a severed head of an unidentified man. The videos showed what the magazine described as "legitimate" military operations in which suspected militants were killed, but the magazine also noted it was a violation of military rules for the soldiers to share the videos among them.

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In a statement, the Army said the photos published by Rolling Stone are "disturbing and in striking contrast to the standards and values of the United States Army," and it "apologizes for the distress these latest photos cause."

The statement said "accountability remains the Army's paramount concern in these alleged crimes. Accordingly, we are in the midst of courts-martial, and we continue to investigate leads."

According to the magazine, the photos were from the "Kill Team, " soldiers with the 5th Stryker Brigade stationed near Kandahar, who conducted premeditated murders of Afghan civilians in cold blood. The photos first appeared in Germany's Der Spiegel magazine.

In the statement, the Army promised to "relentlessly pursue the truth, no matter where it leads, both in and out of court, no matter how unpleasant it may be, no matter how long it takes."

It calls on to "allow the judicial process to continue to unfold and be mindful that the government has distinct obligations to the victims and to the accused, which include compliance with the court's protective order to ensure a fair trial."

It said the Army is "troubled that any soldier would lose his 'moral compass'," and vowed to "do whatever we need to as an institution to understand how it happened, why it happened and what we need to do to prevent it from happening again."