A/HRC/10/22 page 24 than 50,000 displaced persons sought refuge in UNRWA schools. Many were also displaced because their homes had been destroyed or become uninhabitable, especially in rural areas.63 On a number of occasions, the Israel Defense Forces also warned or ordered the civilian population to flee areas or sites, which were often attacked shortly thereafter. 83. International law prohibits arbitrary displacement, a notion that includes displacement in situations of armed conflict that is incompatible with international humanitarian law because it is not warranted by the security of the civilians involved or imperative military reasons.64 84. The conduct of the hostilities exacerbated forced displacement within Gaza. The Israel Defense Forces resorted to aerial bombardment and artillery shelling in densely populated areas of Gaza, reportedly disregarding the above-mentioned standards and the general rules of international humanitarian law concerning the targeting of objects (see paragraph 102 below). Incidents of Palestinian combatants placing military installations close to civilians or civilian objects, thereby increasing the danger for the civilian population and triggering their displacement, were also reported. 85. Displaced persons also became victims as a consequence of military attacks. On 6 January 2009, Israeli shelling is reported to have killed 37 persons and injured 55 outside a UNRWA school in Jabalya that sheltered a large number of displaced persons at the time (see annex). 86. When the present report was finalized, thousands of persons remained homeless because their homes had been destroyed or damaged during the fighting; the total number of displaced was unknown. Most displaced persons are staying in poor, overcrowded living conditions with host families who are already overstretched and face shortages of food, non-food items (such as mattresses and blankets), water and electricity. Continuing a 19-month blockade of Gaza, which had created a serious humanitarian crisis even before the military incursion began, Israel still restricts access to Gaza for goods urgently required to address emergency humanitarian needs and to permit rehabilitation and reconstruction efforts. On 9 February 2009, the Office for the Coordination of Humanitarian Affairs, in a field update, reported that international agencies had faced unprecedented denial of access to Gaza since 5 November 2008. 87. Some of the recently displaced persons within Gaza, especially in rural areas, are Palestinians belonging to families from Gaza, the West Bank and East Jerusalem. The remainder are Palestinian refugees, who fled or were driven from their homes on the territory inside the State of Israel or their descendants. The renewed displacement of Palestinian refugees inside Gaza creates additional vulnerabilities for them. 63 Initial estimates indicate that over 4,240 residences were destroyed and 44,306 were damaged, most of them rendered inhabitable without considerable rehabilitation. 64 Guiding Principles on Internal Displacement (E/CN.4/1998/53/Add.2), principle 6, restating articles 12 of the International Covenant on Civil and Political Rights and customary international humanitarian law (ICRC study, rules 24 and 129-131). See also chapter II.