Officials say gunmen went on killing sprees in Pakistan’s largest city after the assassination of a lawmaker, killing at least 37 people. Dozens of vehicles and shops were set on fire as security forces struggled to gain control. The latest unrest in the southern city of more than 16 million came after Raza Haider, a provincial lawmaker, was shot dead along with his bodyguard in a mosque in Karachi’s Nazimabad area while preparing to offer prayers on Monday. Officials from different hospitals put the total death toll by Tuesday morning at 37. Sindh province spokesman Jamil Soomro said at least 10 people were arrested, and that police and Army Rangers were dispatched throughout the city to impose order. But gunfire could still be heard Tuesday morning.