Attack or bombardment of undefended towns - Art. 2.
Art. 2. The bombardment by whatever means of towns, ports, villages or buildings which are undefended is prohibited in all circumstances. A town, port, village or isolated building shall be considered undefended provided that not only (a) no combatant troops, but also (b) no military, naval or air establishment, or barracks, arsenal, munition stores or factories, aerodromes or aeroplane workshops or ships of war, naval dockyards, forts, or fortifications for defensive or offensive purposes, or entrenchments (in this Convention referred to as "belligerent establishments") exist within its boundaries or within a radius of "x" kilometres from such boundaries.