When a bomb that might be triggered by a ringing mobile terminal is suspected of being located within a target zone, the base stations whose coverage areas include a critical area that surrounds and encompasses that target zone are switched into a one-way calling mode that prevents the mobile terminals within that critical area from receiving incoming calls, but still allows users of those mobile terminals to place to place outgoing calls. The one-way calling mode is effected in response to a signal received by a base station from its associated MSC that instructs it to disable its paging function, thereby preventing the mobile terminal from receiving and responding to a signal that indicates that an incoming call is present, and thus prevents the base station from sending a signal to the mobile terminal that activates its ringing circuitry.