Syrian rebels claim to have taken full control of a Scientific Research centre in Aleppo.<br /><br /> Amateur video shows fierce clashes with government forces, described as the most intense insurgent offensive in the city in three years.<br /><br /> Several rebel groups including ISIL militants are fighting forces loyal to President Bashar al-Assad for control of Aleppo, which has been partitioned since 2012.<br /><br /> Government troops say they’ve carried out heavy air strikes on rebel positions on Friday in retaliation.<br /><br /> The renewed fighting led neighbour Turkey to step up security along its border with Syria.<br /><br /> A military convoy of high ranking soldiers were deployed to the city of Gaziantep.<br /><br /> Aleppo lies just 50 kilometres from the Turkish border.<br /><br /> An insurgent alliance including the al Qaeda-linked Nusra Front and the hardline Islamist Ahrar al-Sham said they had set up a joint operations room to run the offensive to “liberate” Aleppo.<br /><br /> Separately, an explosion at a mosque in Syria’s Idlib province on F
