A huge explosion at a security building in northern Egypt kills at least 11 people and wounds more than 100.<br/> <br />Cars were burned out and the entire city of Mansoura turned to chaos as people rushed to hospitals to check on the victims.<br/> <br />The number of dead is expected to rise and people have been urged to donate blood to the wounded.<br/> <br />A security source says the blast was caused by a car bomb, but it is not clear if it was a suicide attack.<br/> <br />There was no immediate claim of responsibility for Tuesday's blast but state officials blame the violence on Mursi's Muslim Brotherhood party.<br/> <br />The attack comes a month before a vote on a new constitution, that's key to help the country transition from military-backed rule.<br/> <br />Attacks on Egypt's security forces and police have increased since the army removed democratically-elected President Mohammed Morsi in July.<br/> <br />His dramatic exit triggered mass protests in which hundreds of Islamist activists were killed and thousan
