The United Nations has launched an emergency appeal for $613 million to help Palestinians in the Gaza Strip recover from Israel's attack on Hamas. UN Secretary-General Ban Ki-moon said help is indeed urgently needed. He says he was deeply moved by his visit to Gaza and that he gave his word that the UN would help. Speaking to reporters at the World Economic Forum on Thursday, Ban said the appeal covers the requirements of UN and other aid organizations for the next six to nine months, and will help provide everything from medical care to clean water. He added that an appeal for longer-term needs would be launched later. In related news, the UN's top relief official accused Hamas of violating international law by its "reckless and cynical" use of civilian shields, but called for Israelis to be held accountable for violating the principle of proportionality in its bombing of UN facilities in Gaza. John Holmes, under-secretary-general for humanitarian affairs and emergency relief coordinator, delivered his assessment during a briefing to the Security Council late Tuesday evening in New York on the work of the UN's Relief and Works Agency (UNRWA) in Gaza. "Even taking into account Israel's security concern to protect its own civilian population, it is clear that there are major questions to be asked about the failure of the Israeli Defense Force to protect effectively civilians and humanitarian workers in Gaza," Holmes told the Council. He told reporters after his briefing that he believed the members of the Security Council believed UN human rights investigators "should be looking at both sides." Holmes added that UNRWA was consulting with members of the Security Council about conducting independent investigations under the auspices of the Council, the UN Secretary-General's office or the General Assembly but refused to elaborate. Israeli teams are conducting an investigation into the attacks and are scheduled to deliver their findings to the UN Secretary-General Ban Ki-moon. Palestinian envoy Riyad Mansour said after Holmes's briefing that any evidence gathered should be forwarded "very soon" to an international court to begin prosecutions of those "among the Israelis, whether they are officers or officials of government, who made the decisions to commit these atrocities." Holmes and his deputies have repeatedly castigated Israel for targeting UNRWA facilities, including a school. More than 50 people sheltering in UN facilities were killed during the conflict. "UN premises should be precious," Holmes told reporters, then corrected himself at the prompting of UNRWA commissioner-general Karen Abu Zayd, saying "sacred is a better word." In his comments, Holmes pressed for the reopening of crossings into Gaza to permit the free flow of goods and cash into Gaza beyond what was permitted before the recent offensive, despite Israeli concerns about "dual-use" goods that could be converted to military use. "Let me emphasize again here the unacceptability of the status quo ante, with a limited trickle of items into Gaza continuing the effective collective punishment of the civilian population," Holmes told the Security Council. He said in his comments to reporters that UNRWA would work with "whoever we need to work with on the ground" to deliver humanitarian relief, including Hamas, but called for immediate Palestinian reconciliation talks. A report by a former legal adviser to UNRWA, released Wednesday by the Washington Institute for Near East Policy, advised the US to push for stricter guarantees that UNRWA assistance was not being used to support members or financial supporters of "specified and unspecified terrorist groups" - a list he suggested could include Hamas.