U.S. and Iraqi leaders have vowed to track down the men who captured and beheaded a 26-year-old American contractor from Philadelphia named Nicholas Berg. A video of the beheading appeared on a website Tuesday connected to Al Qaeda. The killers said the murder was revenge for the prison abuse of Iraqis taking place at the Abu Ghraib prison. The video captures Berg saying “My name is Nick Berg, my father’s name is Michael, my mother’s name is Suzanne. I have a brother and sister, David and Sarah.” The group that carried out the murder claimed it had ties to Abu Musab al-Zarqawi. In a statement the group said “The worst is coming and, God willing, the tough days are still to come. You and your soldiers will regret the day that you touched the ground of Iraq.”” Berg was working in Iraq as an independent businessman fixing communication antennas. He was last seen on April 9. He was originally scheduled to return home to the United States on March 30, but a week before his departure he was detained by Iraqi police at a checkpoint in Mosul and turned over to U.S. officials. He was held for 13 days though it remains unclear as to why. He was released on April 6, a day after his family filed a suit in federal court against the US charging that the US was illegally holding their son. Three days after his release he was to never be seen again. His decapitated body was found Saturday on a highway overpass in Baghdad. His father, Michael Berg, said Nicholas may still be alive if he had been allowed to leave the country on March 30 when he was scheduled to. He said '’He was arrested and held without due process. The time he got out, the whole area was inflamed with violence.'’