A/HRC/15/50 opening of an investigation to be unreasonable.24 When examining the progress of investigations, frequent and unexplained adjournments can unacceptably compound delay.25 26. The Committee must determine what standards are applicable to investigations in the present context. Both Israel and the Palestinian side have a duty to investigate alleged serious violations of IHL and IHRL. This duty arises as a result of international law and is further imposed by General Assembly resolution 64/254. 27. As extensively explained in the FFM report,26 all parties to the armed conflict are bound by the relevant rules of IHL. Israel is a party to the Fourth Geneva Convention and is, moreover, bound by the rules of customary international law reflected in the 1907 Hague Regulations concerning the Laws and Customs of War on Land and Additional Protocol I of 1977. Palestine is not a party to any of the relevant international instruments. However, in June 1989, the Palestinian Authority submitted a unilateral written undertaking to Switzerland, the depositary of the Geneva Conventions, to be bound by the four Geneva Conventions of 1949 and the two Additional Protocols of 1977.27 This declaration established a binding commitment under international law.28 Additionally, both the Palestinian Authority and the de facto Gaza authorities are subject to the IHL rules of customary international law that apply to non-State actors. 28. With regard to inquiries into alleged violations of IHRL, Israel has accepted legal responsibility to investigate by ratifying the International Covenant on Civil and Political Rights and the Convention against Torture. As clarified by the International Court of Justice, the Covenant is applicable also to actions by Israel in the occupied Palestinian territory.29 The Palestinian Authority has pledged to respect international human rights law by several declarations addressed to the international community30 and by enshrining that commitment in its Basic Law (arts. 9–33). Lastly, the de facto Gaza authorities have made a series of unilateral declarations of respect for human rights and have acknowledged that the Palestinian Basic Law applies to the Gaza Strip.31 29. The question remains whether the more elaborate IHRL standards on investigations also govern inquiries into violations of IHL. In principle, IHRL continues to apply during armed conflict alongside IHL, subject to the possible derogation of certain civil and political rights in states of emergency. IHL may prevail as lex specialis.32 There is no 24 25 26 27 28 29 30 31 32 See Halimi-Nedzibi v. Austria, application No. 8/1991, 18 November 1993, para. 13.5; M’Barek v. Tunisia, case 60/1996, 10 November 1999, paras. 11.5–11.7. Musayev and Others v. Russia, para. 160. A/HRC/12/48 paras. 270–285, 304. On 13 September 1989, the Swiss Federal Council informed the States parties that it was not in a position to decide whether the letter constituted an instrument of accession “due to the uncertainty within the international community as to the existence or non-existence of a State of Palestine”. See Nuclear Tests (Australia v. France), Judgment, I.C.J. Reports 1974, p. 253 (p. 267, para. 43). Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, I.C.J. Reports 2004, p. 136 (pp. 179–180, paras. 109–111). See, for instance, the Barcelona Declaration of the Euro-Mediterranean Ministerial Conference, 27– 28 November 1995. A/HRC/12/48, para. 307. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996, p. 226 (p. 240, para. 25); Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territories, Advisory Opinion, I.C.J. Reports 2004, p. 136 (p. 178, para. 106); Case concerning Armed Activity on the Territory of the Congo (Democratic Republic of Congo v. Uganda), Judgment, I.C.J. Reports 2005, p. 168 (p. 243, para. 216); Application of the International Convention on the 9