SIBI - Militants targeted a vehicle of a law enforcement agency at Chakar Khan Road here on Thursday killing a security man and injuring three others.  According to details, militants exploded material through remote-controlled device near the patrolling vehicle that was passing through Chakar Khan Road. One security man was killed and three others including a civilian were injured.   The injured were shifted to hospital. After the blast, police and other security agencies surrounded the area and officials were alerted on exit points to increase checking and nab the culprits.