0031-0330 irl.qxd 2.3.2009 14:20 Page 175 PROTECTION OF CIVILIAN PERSONS 175 b) civilian persons who take no part in hostilities, and who, while they reside in the zones, perform no work of a military character. When the Parties concerned have agreed upon the geographical position, administration, food supply and supervision of the proposed neutralized zone, a written agreement shall be concluded and signed by the representatives of the Parties to the conflict. The agreement shall fix the beginning and the duration of the neutralization of the zone. ART. 16. — The wounded and sick, as well as the infirm, and expectant mothers, shall be the object of particular protection and respect. As far as military considerations allow, each Party to the conflict shall facilitate the steps taken to search for the killed and wounded, to assist the shipwrecked and other persons exposed to grave danger, and to protect them against pillage and ill-treatment. Wounded and sick ART. 17. — The Parties to the conflict shall endeavour to conclude local agreements for the removal from besieged or encircled areas, of wounded, sick, infirm, and aged persons, children and maternity cases, and for the passage of ministers of all religions, medical personnel and medical equipment on their way to such areas. II. Evacuation ART. 18. — Civilian hospitals organized to give care to the wounded and sick, the infirm and maternity cases, may in no circumstances be the object of attack, but shall at all times be respected and protected by the Parties to the conflict. States which are Parties to a conflict shall provide all civilian hospitals with certificates showing that they are civilian hospitals and that the buildings which they occupy are not used for any purpose which would deprive these hospitals of protection in accordance with Article 19. Civilian hospitals shall be marked by means of the 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, but only if so authorized by the State. The Parties to the conflict shall, in so far as military considerations permit, take the necessary steps to make the distinctive emblems indicating civilian hospitals clearly visible to the enemy land, air and naval forces in order to obviate the possibility of any hostile action. III. Protection of hospitals I. General protection