KARACHI: At least 55 people have been killed as a powerful earthquake struck southwest Pakistan on Tuesday, Kalat Commissioner said. According to the Meteorological Department, the epicentre of the 7.7 magnitude earthquake was 120Km southwest of Khuzdar in Balochistan province at a depth of 23 kilometres. The US Geological Survey measured the earthquake at 7.8. Tremors which began at 16:29 (PST) were felt for two minutes in several cities of