CRC/C/NIC/CO/4 (c) Establish separate detention centres for persons below the age of 18 and improve detention conditions, including ensuring the full exercise of the rights of the child while in police custody; (d) Investigate and prosecute all cases of ill-treatment committed by law enforcement officers, particularly prison guards, and establish an independent, accessible mechanism for receiving and dealing with complaints from children, which takes account of children’s sensibilities; and (e) Ensure prompt approval by the Supreme Court of the draft procedural manuals and protocols on alternatives to privation of liberty, implementation and monitoring of sanctions and interdisciplinary teams for psychosocial care. Protection of witnesses and victims of crimes 82. The Committee recommends that the State party ensure, through adequate legal provisions and regulations, that all children victims (e.g. of abuse, domestic violence, sexual and economic exploitation, abduction and trafficking) and/or witnesses of such crimes are provided with protection as required by the Convention, and take full account of the United Nations Guidelines on Justice in Matters Involving Child Victims and Witnesses of Crime, annexed to the Economic and Social Council resolution 2005/20 of 22 July 2005. Children belonging to indigenous and minority groups 83. The Committee notes that the rights of indigenous peoples and ethnic communities of African descent are formally recognized in the Constitution and in the Autonomy Law. However, the Committee is concerned that indigenous and Afro-descendant children face significant challenges in exercising their substantive rights under the Convention, more specifically the right to enjoyment of their culture and language. 84. The Committee recommends that the State Party: (a) Promote the right to be heard with regard to indigenous and Afrodescendant children in decision-making and cultural life; (b) Monitor and evaluate the integration of indigenous and Afro-descendant children’s rights in national plans and programmes; (c) Ensure that the rights of indigenous and Afro-descendant children are specifically protected with regard to their culture and language, particularly in the provision of access to basic services, and by promoting culturally- and linguisticallysensitive education and health policies and programmes; and (d) Take into account the Committee’s general comment No. 11 (2009) on indigenous children and their rights under the Convention (CRC/C/GC/11). 9. Ratification of international human rights instruments 85. The Committee recommends that the State party ratify the core United Nations human rights instruments to which it is not yet a party, namely the Convention for the Protection of All Persons from Enforced Disappearance, the Optional Protocol to the Convention on the Elimination of all forms of Discrimination against Women and the Optional Protocol to the Covenant on Economic, Social and Cultural Rights. 18