The Islamic State of Iraq and the Levant has reportedly executed over 100 activists of another opposition group. <br /><br />Its believed to have happened north of Al Raqqa.<br /> <br />It comes as Syrian government forces are advancing on rebel positions on the outskirts of Aleppo city. <br /> <br />Activists say opposition fighters could lose the strategic district of Sheikh Najjar.<br /> <br />Al Jazeera's Andy Gallacher explains.
