(a)any work of defence, arsenal, naval, military or air force establishment or station, mine, minefield, camp, ship or aircraft belonging to, or occupied by or on behalf of Government, any military telegraph or telephone so belonging or occupied, any wireless or signal station or office so belonging or occupied and any factory, dockyard or other place so belonging or occupied and used for the purpose of building, repairing, making or storing any munitions of war, or any sketches, plants, models or documents relating thereto, or for the purpose of getting any metals, oil or minerals of use in time of war;