Al Qaeda-linked Islamist rebels have reportedly seized one of Syria’s biggest oil fields, in what would be a major blow to the Assad regime.<br /><br />The raid would cut off the government’s access to almost all crude reserves in eastern Deir<br />al-Zor province.<br /><br />Assad’s forces have gained momentum recently. But the opposition, particularly Islamist factions, still holds large swathes of land in the north and east.<br /><br />Seven leading Islamist groups have just merged to form what could be Syria’s biggest rebel army.<br /><br />The new Islamic Front, seeking to build an Islamic state, could have at least 45,000 fighters. Its creation further undermines Syria’s Western-backed rebels.<br /><br />Fierce fighting rages on with reports of at least 40 people, mostly civilians, being killed on Saturday in government air strikes around the northern city of Aleppo.