Nos casos em que foguetes foram encontrados em escolas da UN estas estavam desocupadas.
http://www.thenation.com/article/180783/five-israeli-talking-points-gaza-debunked

The two cases where Hamas indeed stored weapons in UNRWA schools (http://www.unrwa.org/newsroom/press-releases/unrwa-strongly-condemns-placement-rockets-school), the schools were empty. UNRWA discovered the rockets and publicly condemned the violation of its sanctity.