Supporters of Benazir Bhutto, the assassinated former Pakistani prime minister, have held a special prayer ceremony in her home town marking the second anniversary of her killing. <br /><br />She was campaigning in the city of Rawalpindi in 2007, when she was shot. <br /><br />Authorities have still not arrested those responsible for Bhutto's death.<br /><br />Al Jazeera's Imran Khan reports
