The video was posted on an Internet forum used by Islamic militants and was accompanied by a written statement from a group identifying itself as the Islamic Army in Iraq. The statement claimed responsibility for the downing of the civilian helicopter carrying security contractors in which 11 people — six Americans, three Bulgarians and two Fijians_ were killed.

The chartered flight was believed to be the first civilian aircraft shot down in Iraq since the U.S.-led invasion two years ago.

There was no independent confirmation of the authenticity of the video, which showed very little editing and bore the clumsy handiwork of an amateur cameraman. Wreckage visible in the video resembles that seen in aftermath footage filmed by various news outlets at the crash site north of Baghdad.

The video begins with an unseen cameraman breathing heavily and running with the camera toward burning wreckage. Two bodies are visible, one of them severely charred, nearly all its clothes burned away.

"Look at that filth," someone says in Arabic.

There are brief glimpses of a man carrying an assault rifle along with the cameraman.

The scene moves to tall grass, where a man with thinning, gray hair and wearing a blue flight suit is lying on his back, the right side of his head bloody. The helicopter's three-man crew was Bulgarian, and it appeared that the man shot in the video was one of the crew.

"Stand up! Stand up!" the cameraman shouts to him in English.

"I can't, it's broken. Give me a hand," the survivor says in accented English, raising his hands for help. "Give me your hand."

It appears the militants help pull him to his feet.

"Weapons?" the gunmen shout at him in Arabic.

The cameraman tells the crewman, whose face is visible, to step back.

"Go! Go!" he shouts.

The survivor then tries to walk, limping with his back to the insurgents, who say something to him that makes him turn around. He raises his hands to somebody off camera as if gesturing to them to stop what they are about to do.

"Carry out God's verdict," someone is heard saying, and the militants shoot the man at point-blank range, continuing even after he falls to the ground. One gunman shouts, "Allahu akbar!"

The Bulgarian-owned helicopter was carrying six American security contractors who worked as bodyguards for U.S. diplomats. Its three crew members were Bulgarian, and two other passengers were Fijian helicopter security guards.

In their Web statement, the Islamic Army in Iraq said it killed the surviving crewman "in revenge for the Muslims killed in the mosques of Fallujah." It apparently referred to the Nov. 13 shooting of a wounded Iraqi by an American soldier in a Fallujah mosque during a U.S. offensive in the city.