Al Qaeda’s leader Ayman al-Zawahiri has called for jihadists all over the world to stage attacks against the United States in an audio video which surfaced on Wednesday. The Egyptian head of the terrorist organisation, who took over from Osama Bin Laden after he was killed in 2011, is believed to be hiding out in Pakistan as his predecessor did before his death. In the 30-minute video, Al-Zawahiri said the wave of Jihad was “expanding” and stressed the internationalism of the movement. _______________ Read more: _______________ He also called for unity among Jihadists, praising Bin Laden for bringing together Muslims around critical issues. The video comes days after British newspapers reported that Bin Laden’s youngest son Hamza Bin Laden, 28, has become subject to a “kill or capture” mission by a Joint Coalition Special Operations Unit, which includes 40 SAS soldiers. Hamza is believed to be in Syria, having escaped the compound in Pakistan where his father was killed shortly before it was infiltrated by US navy seals. The CIA added Hamza to the US terror watch list after intelligence sources identified him in Syria in May, fearing he is planning revenge attacks for his father’s killing against the West. Bin Laden’s favourite son is rumoured to have become the new leader of Al Qaeda as Al-Zawahiri has struggled to gain loyalty in the group, which has been overshadowed by ISIL. "Hamza, by contrast, suffers from none of these handicaps," counter-terror expert Ali Soufan wrote in an academic journal. "His family pedigree, not to mention his dynastic marriage to the daughter of an al Qaeda charter member, automatically entitles him to respect from every jihadi who follows bin Laden's ideology."