The Marine Corps said Wednesday that it is investigating the origins of a video on the Internet that purports to show Marines in combat gear urinating on the corpses of three Taliban insurgents.

The brief video, which runs for less than a minute, began circulating on Web sites early Wednesday. It depicts four Marines laughing as they relieve themselves while standing over three prostrate bodies.

A caption asserts that the Marines are part of a scout sniper team with the 3rd Battalion, 2nd Marines, an infantry unit from Camp Lejeune, N.C. Members of the unit were deployed to Afghanistan last year but returned in September.

Capt. Kendra N. Hardesty, a Marine Corps spokesman, said officials would “fully investigate” the matter but so far have been unable to verify the video’s authenticity or if members of the battalion were involved.

Warning: the video includes graphic images.

“The actions portrayed are not consistent with our core values and are not indicative of the character of the Marines in our Corps,” she said in a statement.

There was no way to determine independently where the video was filmed or the identities of those involved.

The caption refers to the corpses as “dead Talibans,” but it was unclear if they were civilians or fighters killed after a battle. The bodies are dressed in Afghan-style clothing; the chest of one male corpse appears to be soaked in blood.

Digital videos and photography have become increasingly common on the battlefield and many of the amateur productions wind up on the Internet. On occasion, the trend has caused severe embarrassment for the U.S. military, or in rare cases, such as the Abu Ghraib scandal in Iraq, triggered international controversy and legal action against those involved.

The Pentagon has sent mixed messages on social media, reviewing troops’ blogs for inappropriate content and classified information at the same time as it has encouraged units and commanders to communicate through Facebook. In embracing social media the Pentagon has effectively acknowledged that it simply cannot stop the flood of data and images from the battlefield.

In 2010, members from the 5th Stryker Combat Brigade, 2nd Infantry Division, photographed themselves posing with corpses of Afghan civilians who were gunned down by a self-proclaimed “kill team” of rogue soldiers. In that case, however, the Army confiscated hundreds of photographs and successfully kept them out of the public domain for months.

A few were later obtained and published last March by two news magazines -- Rolling Stone and Der Spiegel, a German publication -- but the impact was muted. Unlike the purported video of the Marines, those photos did not depict troops in the act of desecrating corpses.

For the latest on this story, including reaction from U.S. Defense Secretary Leon Panetta and Afghan President Hamid Karzai, click here.

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