In Jharkhand, three policemen including a Sub Inspector of Police have been killed and four others injured in a landmine blast triggered by the Maoists. The incident took place at a diversion on NH- 29 near Khranji-Tungri under Balumath police station in Latehar district on Wednesday.The blast occurred when the police party was patrolling the area. The injured policemen were shifted to hospitals in Ranchi.