Security forces cleared a five-storey police building in Karachi on the city’s main thoroughfare in an hours-long operation during which three terrorists were killed while four others died on Friday evening. At least 19 men, mostly security personnel, were injured in the exchange of fire with Tehreek-i-Taliban Pakistan (TTP) terrorists who stormed the heavily guarded premises. Just half an hour after sunset, three militants hurled a hand grenade at the gate of the building. The terrorists brought with them “three bags of food”, indicating their preparation for a prolonged siege, DIG East-Zone Muquddas Haider, who was among the senior officers leading the operation, told Dawn. He said one of the terrorists blew himself up on the fourth floor of the building during the operation while two others were shot dead on the rooftop. Last month, 101 people were killed as TTP terrorists attacked a mosque located in the police lines in Peshawar.