Sources : ` ` There are other Americans who are being targeted '' by ISIL . Mohammed Hamzah Khan made his first public appearance . It was not immediately clear how many had joined ISIS and how many were with other groups opposed to the Syrian government . The 19-year - old was arrested at O'Hare International Airport on Friday . Police allege there is evidence that he wanted to join ISIS .
Sources : ` ` There are other Americans who are being targeted '' by ISIL . Mohammed Hamzah Khan made his first public appearance . The 19-year - old was arrested at O'Hare International Airport on Friday . Police allege there is evidence that he wanted to join ISIS .