A/HRC/33/38 violation and to the relevant victims and witnesses, they endeavour to reach those victims and witnesses in other ways, duly considering the impact on the weight information so obtained could be given. 6. In preparing the present report, OHCHR sent letters to a broad range of Governments and organizations, including civil society organizations and human rights organizations in Yemen and a range of international organizations. The Office received and duly considered all the information it received in response, including information from the Government of Yemen and the Government of Saudi Arabia and from national political organizations, civil society organizations and human rights organizations.2 Where the report includes data or statistics gathered by credible partner organizations, including official bodies, intergovernmental and non-governmental organizations, and the media, the source of the information is clearly cited, and it is indicated whether OHCHR was able to corroborate the information. 7. OHCHR employs a “reasonable ground” standard in its assessment of incidents investigated. The assessment in each case considers the credibility and reliability of the source, taking into account its nature and objectivity, the quality of previously submitted information and the methodology utilized by the source, and the validity of the information itself, which is cross-checked through witness statements and other sources of information. III. Legal framework 8. Yemen is a party to seven of the nine core international human rights treaties and to the Optional Protocols to the Convention on the Rights of the Child on the involvement of children in armed conflict and on the sale of children, child prostitution and child pornography. As a party to those instruments, Yemen is legally bound to respect, protect and fulfil the human rights of those within its jurisdiction. Despite approval by the Cabinet, the Parliament has yet to approve the ratification of a number of human rights instruments, namely, the International Convention for the Protection of All Persons from Enforced Disappearance, the Rome Statute of the International Criminal Court, the Optional Protocol to the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment and the Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children, supplementing the United Nations Convention against Transnational Organized Crime. 9. Yemen is a party to all four Geneva Conventions of 12 August 1949 and to Additional Protocols I and II thereto, and to the Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons Which May Be Deemed to Be Excessively Injurious or to Have Indiscriminate Effects. Yemen has not accepted individual complaints procedures provided for under the various international human rights treaties, with the exception of the procedure provided for under the Optional Protocol to the Convention on the Rights of Persons with Disabilities. 10. All parties to the conflict in Yemen, including members of the coalition forces,3 are obliged to respect the applicable rules of international humanitarian law, including the principles of precaution, distinction and proportionality. Civilians and civilian objectives must be protected at all times. Hospitals, schools and religious sites are subject to 2 3 4 A total of 194 reports were submitted by 37 national organizations and 67 reports were submitted by 7 international organizations. Three United Nations agencies provided reports. The coalition consists of all the States members of the Gulf Cooperation Countries (with the exception of Oman), as well as Egypt, Jordan, Morocco, Senegal and the Sudan.