For purposes of this section, the term “Customs security area” means the Federal inspection services area at any airport accommodating international air commerce designated for processing passengers, crew, their baggage and effects arriving from, or departing to, foreign countries, as well as the aircraft deplaning and ramp area and other restricted areas designated by the port director. These areas will be posted as restricted to the extent possible and are established for the purpose of prohibiting unauthorized entries or contact with persons or objects.