Under certain circumstances, persons and objects that are protected under international humanitarian law lose the protection conferred upon them. In such cases, they may become lawful military objectives.
Such a loss of protection can occur when persons protected against attack directly participate in hostilities, or when civilian objects are used for military purposes. In addition, if medical personnel commit or medical objects are used to commit acts harmful to the enemy, outside their humanitarian function, lose their special protection and may even be attacked if they directly participate in hostilities (persons) or turn into military objectives (objects).
See Status; Military objectives; Direct participation in hostilities; Loss of Status; Protected Persons;
LEGAL SOURCE
for wounded, sick and shipwrecked or persons otherwise hors de combat, parachuting airmen in distress
for act of hostilities
PI, 8(a)-(b), 41 and 42
for civilians
When DPH: See Direct participation in hostilities
for civilian objects
if military contribution
for civil defence objects
for cultural, spiritual objects
Hague Convention on Cultural Property, Arts. 4/2, 11 and 19
for medical objects
for acts harmful to the enemy
GCI, 21 (see ICRC updated Commentary) and 35 (see ICRC updated Commentary)
GCII, 34 (see ICRC updated Commentary)
other specially protected objects
CASE
Afghanistan, Attack on Kunduz Trauma Centre
Afghanistan, Bombing of a Civilian Truck
Iraq/Syria/UK, Drone Operations against ISIS
Israel/Palestine, Accountability for the Use of Lethal Force
Eastern Ukraine, Attacks Against and Military Use of Schools
Eastern Ukraine, OHCHR Report on the Situation: November 2016 - February 2017
Central African Republic, No Class: When Armed Groups Use Schools
Georgia: Attacks against peacekeepers