(SOUNDBITE) (English) UNKNOWN ISLAMIC STATE FIGHTER, SAYING:<br/> <br />"This is Peter Kassig, a U.S. citizen of your country."<br/> <br />Islamic State claim they have beheaded American hostage Peter Kassig -- taken captive on his way to eastern syria in 2013 to do humanitarian work.<br/> <br />This new video posted online does NOT show the beheading... it shows a masked man standing with a decapitated head covered in blood lying at his feet.<br/> <br />Islamic State, seen here in file video, released the 15-minute video which also shows the militants beheading at least 14 men, which they say were pilots and officers loyal to Syrian President Bashar al-Assad.<br/> <br />The U.S. government is trying to confirm the authenticity of the video.<br/> <br />(SOUNDBITE) (English) UNKNOWN ISLAMIC STATE FIGHTER, SAYING<br/> <br />"Peter, who fought against the Muslims in Iraq while serving as a soldier under the American army, doesn't have much to say."<br/> <br />Kassig's parents said in a statement Sunday morning they were aware o
