KARACHI: Attackers hurled a cracker at a Rangers checkpost in North Nazimabad area on Friday, police said.SSP Central Muqaddas Haider said attackers threw the cracker on a Rangers checkpost from over a bridge in North Nazimabad’s Block B. The bomb went off with a loud explosion spreading fear and panic in the area. However, Rangers personnel remained unhurt. According to Bomb Disposal Squad, the cracker was a home-made bomb and 250 grams of explosive material was used in its making. Later in the day, a cracker was thrown in Liaquatabad supermarket which exploded with a loud bang. No injuries were reported in this incident too, SSP Muqaddas said. Law-enforcement personnel are regularly targeted in Karachi where an extensive operation against criminal elements was initiated back in September 2013.