Videos obtained by Syrian opposition activists show executions , interrogations . The ringleader , Abu Ahmed al-Iraqi , may be leader of Islamic State in Iraq and Syria . Comment: Al Qaeda leader Ayman Al-Zawahiri calls for the group to leave Syria .
Videos obtained by Syrian opposition activists show executions , interrogations . The ringleader , Abu Ahmed al-Iraqi , may be leader of Islamic State in Iraq and Syria . ISIS is a jihadist group opposed to the regime of Syrian President Bashar al-Assad . Al Qaeda leader Ayman Al-Zawahiri calls for the group to leave Syria .