In this Friday, Nov. 02, 2012 photo, a rebel fighter walks across the debris of damaged residential buildings in Karm al-Jebel after several days of intense clashes between rebel fighte

 

              In this Friday, Nov. 02, 2012 photo, a rebel fighter walks across the debris of damaged residential buildings in Karm al-Jebel after several days of intense clashes between rebel fighte
In this Friday, Nov. 02, 2012 photo, a rebel fighter walks across the debris of damaged residential buildings in Karm al-Jebel after several days of intense clashes between rebel fighters and the Syrian army in Aleppo, the Syria. U.N. officials and human rights groups believe President Bashar Assad's regime is responsible for the bulk of suspected war crimes in Syria's 19-month-old conflict, which began as a largely peaceful uprising but has transformed into a brutal civil war. However a video that appears to show a unit of Syrian rebels kicking terrified, captured soldiers and then executing them with machine guns raised concerns Friday about rebel brutality at a time when the United States is making its strongest push yet to forge an opposition movement it can work with. (AP Photo/Narciso Contreras)