Pakistan's former military ruler Pervez Musharraf has appeared before an anti-terrorism court over the murder of former Prime Minister Benazir Bhutto. Musharraf is accused of failing to provide enough security for Bhutto, who was assasinated in 2007. It is one of three cases he's fighting in the courts since returning home last month after four years in exile. Al Jazeera's Imtiaz Tyab reports from Islamabad.