A/HRC/19/20 of certain materials qualified by Israel as “dual-use” items, impeding reconstruction, maintenance and expansion of civilian infrastructure destroyed during Operation Cast Lead and as a result of ongoing military operations.35 There was also a delay in the construction of three wastewater treatment plants. The inability to build new schools/classrooms due to the lack of construction material in combination with the growing population has led to a double- and triple-shift system of holding classes, which negatively affects the quality of education that children receive. About 85 per cent of schools in Gaza run on the system of double or triple shifts, leading to a reduction in class time and the elimination of extracurricular activities.36 The unemployment rates continue to increase, with an estimated 26 per cent of the people, including 38 per cent of the youth, being unemployed.37 Due to ongoing restrictions on the import of construction materials, the lack of alternative employment opportunities, and huge housing and infrastructure needs, the tunnel economy continues to grow. 38. Palestinians continued to face serious threats to life, liberty and security on a regular basis as a result of various forms of violence, including conflictrelated violence (such as incursions, bombardments/air strikes and levelling operations by Israeli security forces) and the use of live ammunition to enforce the access to restricted areas on land and at sea. Such acts, which usually take place with impunity, have resulted in death, injury, displacement, disability and/or psychological trauma, as well as extensive damage to civilian infrastructure38 and Palestinian land and property. 39. In some cases, IDF failed to take precautions to avoid the loss of civilian life. It has also failed to observe the principles of proportionality and distinction. OHCHR investigated four cases of civilians killed by IDF in Gaza where necessary measures to prevent the casualties were not taken. On 22 March 2011, an Israeli mortar shell struck a civilian residence in Al-Tufah neighbourhood, eastern Gaza city, killing four civilians, including two children, and wounding 12 others. Earlier that day three mortar shells targeting IDF stationed at the Green Line had been launched from the area.39 The shells had caused no physical injuries or damage. While IDF seems to have been responding to the earlier attack from the area, it is alleged it did so several hours later. This time frame should have allowed IDF to use all means at its disposal to properly assess whether a military objective was still present in the area so long after the initial attack as well as the risk to civilians in the targeted area and allowed it to choose weapons which could have minimized this risk. On 8 April 2011, an IDF missile struck a house in Abassan Al Kabira in Khan Younis, killing a mother (40 years old) and her daughter (19 years old), and injuring two children who were sitting in the courtyard. Witnesses interviewed by OHCHR noted that no mortar shell or rocket attacks at Israeli targets had taken place from that area on the day of the strike or before. 35 36 37 38 39 14 OCHA, Monthly Humanitarian Monitor, July 2011, pp. 8-9. UNICEF oPt monthly update, July-August 2011, p. 1. OCHA, Humanitarian Situation in the Gaza Strip, fact sheet, October 2011, first page. Available from www.ochaopt.org/documents/ocha_opt_Gaza_FactSheet_October_2011_english.pdf. For example, a well and nine water tanks were destroyed during an Israeli air strike in Beit Hanoun on 17 July 2011. According to the United Nations Department of Safety and Security, communication dated 26 June 2011.