BAGHDAD, Iraq – Gunmen shouting “God is Great!” dragged the burning body of what they said was an American pilot in a horrific video posted yesterday on the Web by a new Al Qaeda-affiliated group that claimed it shot down an Apache helicopter last weekend.

The American military expressed outrage over the release of “such a despicable video for public exposure,” but said it had serious doubts that the footage was authentic.

The AH-64D Apache Longbow attack helicopter was downed near Youssifiyah about 12 miles southwest of Baghdad on Saturday, killing the two pilots. An American statement said troops had recovered “all available remains” although “reports of a Web site video suggest that terrorists removed part of a body from the crash site.”

The flaming wreckage of a helicopter could be seen clearly in the video, including outlines of the aircraft’s blades and jagged pieces of wreckage strewn over a field. The camera panned over bloodstained debris, then showed several men dragging the burning body of a man across a field as they shouted “Allahu Akbar,” or “God is Great!” Voices could be heard in the background shouting “come, come, help me carry it.”

The body’s face was not visible, but the camera zoomed in on what appeared to be his waistline, which showed a scrap of underwear with the brand name “Hanes.” It appeared the man was wearing tattered digital camouflage fatigues.

The time stamp on the video which shows the minutes and seconds do not run sequentially, and the scenes appear disjointed. The posting also included bombing scenes filmed elsewhere, indicating the material had been edited as a propaganda package.

Lieutenant Colonel Barry Johnson, a spokesman for the command, said the wreckage shown on the video “does appear to be an AH-64” but added that other helicopters of that type have been lost.

“We have serious doubts about the authenticity of this video, a common tactic we see terrorist groups use to keep the stories they want alive in the media,” he said.