An al Qaida-linked group claimed it killed three US soldiers and mutilated two of their bodies to avenge the rape and murder of a young Iraqi woman.
The Mujahedeen Shura Council made the claim in a four and a half-minute video posted on the internet which included the mutilated bodies of two of the soldiers attacked on June 16 near Youssifiyah, south west of Baghdad.
Pictures from the video showing two of the American dead, one of whom had been decapitated were later published.
The militant group said the video was released as "revenge for our sister who was dishonoured by a soldier of the same brigade".
Two sergeants are among five American soldiers charged over the March 12 rape-murder and the killing of the girl's parents and a younger sister.
A previously-discharged soldier had been arrested in the case last month and charged with rape and murder.
The statement by the insurgents said that as soon as fighters heard of the rape and murder "they kept their anger to themselves and didn't spread the news".
"They decided to take revenge for their sister's honour," the statement said. "With Allah's help, they captured two soldiers of the same brigade as this dirty crusader."
The Mujahedeen Shura Council is an umbrella organisation of several Islamic extremist groups, including al Qaida in Iraq.
It claimed responsibility for shooting down a US Apache helicopter in the Youssifiyah area in April.
US investigators had said there was no evidence linking the deaths of the three soldiers last month to the rape-killing.
S gt Paul Cortez, Spc James Barker, Pfc Jesse Spielman and Pfc Bryan Howard are accused of rape and murder and several other charges as participants.
They could face the death penalty if convicted.
A fifth, Sgt Anthony Yribe, is charged with failing to report the attack but is not accused of participating directly.