<br/>A video has been posted on the Internet purportedly showing the killing of civilians by American forces in Baghdad three years ago. The footage, apparently taken from US Appache helicopter gunships showed them firing on a group they took to be armed insurgents. The website publishing the footage said, two of the 12 dead were Television cameramen.<br/><br/> When the incident took place, the US military said the helicopters were engaged in combat operation against a hostile force. The Pentagon has not yet responded to the release of the video.