Three US Marines have pleaded guilty and been sanctioned for urinating on the corpses of Afghan Taliban fighters and posing for pictures with the dead, the Quantico-based unit said Monday.

"Three Marines received non-judicial punishment today for violations of the Uniform Code of Military Justice for their role in the desecration and filming of deceased Taliban that became public in January 2012," said a statement.

"The troops were disciplined under an administrative procedure," it said, without detailing the penalties given, but noting that action against other Marines involved in the incident would be announced at a later date.

The actions depicted in the video took place during a counter-insurgency operation in the restive Musa Qala district of Helmand Province, in southwestern Afghanistan in July 2011.

The video was posted on the Internet, causing great embarrassment to the US military and prompting a Naval Criminal Investigative Service investigation, as well as condemnation and an apology from Secretary of Defense Leon Panetta.

Four Marines from a sniper unit in the 3rd Battalion, 2nd Marines based at Camp Lejeune in North Carolina, were questioned over the scandal in January, when the pictures emerged.

The unit was deployed in Helmand, in southwestern Afghanistan, from March to September last year.

One of the Marines, apparently aware he was being filmed, was heard saying in the video: "Have a great day, buddy," referring to one of the dead.

The scandal was one in a long line to tarnish the image of the US military in the past decade, from the Abu Ghraib prison abuse images in Iraq to more recent convictions of troops who killed Afghan civilians for sport.

Panetta said at the time that the troops' behavior was "utterly deplorable," while US Secretary of State Hillary Clinton spoke of her "total dismay" at the acts, vowing that the culprits would be found and punished.

Monday's statement, from the Marines' public affairs office in Quantico, Virginia, said the three non-commissioned officers pleaded guilty "under the terms of an agreement" and their names would not be released.

It said one Marine admitted violating military law by wrongfully posing for an unofficial photograph with human casualties and urinating on the body of a deceased Taliban soldier, which was "prejudicial to good order and discipline."

Another Marine pleaded guilty to posing for an unofficial photograph with human casualties and making a video recording of the incident.

The third trooper to be punished so far pleaded guilty to "failing to report the mistreatment of human casualties by other Marines," and "making a false official statement" during the Naval Criminal Investigative Service probe.

Punishment from administrative proceedings -- as opposed to courts martial -- can include reduction in rank, restriction to a military base, extra duties, forfeiture of pay, a reprimand, or a combination of such measures.