Several incidents of violence in the metropolis claimed seven lives on Friday, police sources said. One man was killed and six others injued in a grenade and firing attack in New Karachi area near Allahwali chowk. The police sources suspected that motive behind the attack could possibly be extortion related. Another person died of gunshot wounds near Meena Bazaar in Pir Colony area of the city. In a separate incident, a man was killed and another injured when some unknown gunmen opened fire on them near Bait-ul-Mukarram mosque in Karachi’s Gulshan e Iqbal area.