At least four extremists were arrested during a search operation in FR Bannu, report said on Sunday. According to DPO Bannu Sajjad Khan, the action was launched in FR Bannu areas of Janikhel, Bakakhel and Mohamandkhel. Heavy arms and ammunitions were recovered from the possession of the culprits. According to police official, the interrogations with the arrested saboteurs are underway and some revelations are expected.