Miscreants have exploded some cocktails in three poling centers in Bogra at 12pm on Wednesday. The centers are Nararuli Utttoron High School, Yakubia High School and Jubli High School.Police detained a suspected person in this connection from Nararuli Uttoron High School. Confirming the matter, Executive Magistrate Abdur Rahim said, additional police, BGB and RAB were deployed in this center after incident.