WARNING: VIDEO CONTAINS GRAPHIC CONTENT<br/> <br />Ambulances race through the streets of Karachi after a bomb exploded on Wednesday, killing at least four security officials.<br/> <br />Pakistani officials say that the attack targeted Sindh High Court's senior judge, Justice Maqbool Baqar.<br/> <br />At the scene of the attack, residents watched as security officials cordoned off the area.<br/> <br />The remains of burned out police vehicles littered the ground as the wounded were moved to a local hospital.<br/> <br />A Mosque and nearby buildings were also damaged.<br/> <br />No one immediately claimed responsibility for the bombing.<br/> <br />A city of more than 18 million, Karachi has a long history of violence.<br/> <br />It typically sees a dozen murders a day - a combination of political killings, street crime and attacks by the Taliban and sectarian militant groups.
