Four persons, including three security personnel, were injured in an attack on a checkpost on Thursday. The attacker was also killed in police firing. Police sources said police had sealed Vatar entry point after receiving information that suicide bombers were going to attempt to enter the city from Punjab. Police claimed the police party on the check post stopped a vehicle for search when and an assailant hurled a hand grenade which exploded to injure a pedestrian and three police personnel, including an SHO. Police opened fire and killed the attacker. The injured were shifted to district headquarters hospital.