PAKISTAN. Karachi. 1988. Shia Muslims celebrate the Ashura by lacerating their backs with blades attached to chains and use knives to cut their scalp, releasing rivers of blood. Each year the Ashura commemorates the "martyrdom" of Imam Hussein, grandson of the Prophet Mohammed, who was killed in the desert of Kerbala by the Sunni Caliph Yazid. Shia's revere Hussein and his father Ali, as the rightful successor to the prophet. Shia's comprise 20% of Pakistan's Muslim population and Ashura is the main occasion for them to demonstrate their strength as a militant minority.