Convoys of vehicles or hospital trains on land or specially provided vessels on sea, conveying wounded and sick civilians, the infirm and maternity cases, shall be respected and protected in the same manner as the hospitals provided for in Article 18, and shall be marked, with the consent of the State, by the display of the distinctive emblem provided for in Article 38 of the Geneva Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field of August 12, 1949.