Blasts echo through the streets of Aleppo -- and thick smoke fills the air.<br/> <br />This amateur video, which was posted to a social media website, purports to show Syria's second city under a barrage of mortars -- said to be carried out by pro-Assad forces.<br/> <br />Reuters journalists at the scene said rebel fighters seemed battered and overwhelmed, and were running low on ammunition -- amid reports that government troops were gearing up for a ground assault.<br/> <br />Reuters can't independently verify this amateur video.<br/> <br />The sustained violence comes amid news that Syria's Prime Minister Riyad Hijab has defected to join the opposition.<br/> <br />That's according to his spokesman, who spoke to Al Jazeera television.<br/> <br />According to an unnamed Jordanian official, Hijab is "in Jordan with his family".<br/> <br />Syrian authorities say he has been sacked.<br/> <br />While his defection is one of the highest-profile desertions from Assad's political and military circles, some doubt his motives.<br/> <br />One Syrian refugee in Turkey says his defection can't undo past wrongdoings.<br/> <br />(SOUNDBITE) (Arabic) SYRIAN REFUGEE, ABDULMENAN HAJ MAJEED, SAYING:<br/> <br />"The defection of a man who has been fighting for fifteen years against us will not help us at all. The ones who defected a year-and-a-half ago were on our side, but not those now."<br/> <br />On Sunday, al Arabiya television reported that a senior Syrian intelligence officer had also defected to Jordan.
