IRAQ USA BEHEADING

A frame grab taken from website video footage May 11, 2004, shows a man, who identified himself as Nick Berg of Philadelphia (C) as he is grabbed by one of his five masked captors moments before he was executed. Al Qaeda's leader in Iraq beheaded an American civilian and vowed more killings in revenge for the abuse of Iraqi prisoners, an Islamist Web site said on Tuesday. After one of the masked men read out a statement, they pushed Berg to the floor and shouted "God is greatest" above his screams as one of them sawed his head off with a large knife then held it aloft for the camera. It was not immediately possible to verify the authenticity of the tape carried on the Muntada al-Ansar Islamist Web site. REUTERS/Reuters TV QUALITY FROM SOURCE