A/HRC/25/46 October 2012 by the Government of the Democratic Republic of the Congo and the United Nations to end and prevent the recruitment and use of children by national security forces, and sexual violence. 52. The Special Representative conducted this visit with the joint support of UNICEF and the United Nations Organization Stabilization Mission in the Democratic Republic of the Congo, and welcomes the release, since the signing of the action plan, of hundreds of children from the national security forces of the Democratic Republic of the Congo, owing to stronger cooperation between the Government and the United Nations. The Special Representative encourages the authorities of the Democratic Republic of the Congo, with the support of the international community and the United Nations system, to sustain their efforts in enhancing age verification procedures and birth registration, as well as in the fight against impunity. She further encourages the authorities of the Democratic Republic of the Congo to uphold their commitment to exclude perpetrators of grave violations against children from being eligible to integrate into the national security forces or to benefit from amnesty, and encourages them to intensify their efforts in holding perpetrators accountable. However, the Special Representative remains concerned at cases of children being detained without due process by national security forces for their alleged association with rebel movements. 53. The Special Representative also met with victims and civil society representatives to assess the existing gaps in responses to violations against children, and to discuss progress and challenges in the fight against impunity. 54. The Special Representative is concerned at the continued threat from the remaining armed groups in the Democratic Republic of the Congo, and at the high numbers of children present in their ranks. She stresses the importance of any and all strategies for their disarmament and demobilization adequately taking into account the specific protection needs of children. VII. Progress in the development of international law A. Progress in the ratification of the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict 55. The Special Representative continues to mobilize support for the signing and ratification of the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict. During the reporting period, she held bilateral meetings with Member States that had not ratified and/or signed the treaty, and actively briefed regional organizations, civil society, and regional groups on the matter. The Special Representative also highlighted the need for Member States to ratify and implement the Optional Protocol at the 2013 annual treaty event organized by the United Nations Office of Legal Affairs. 56. Between June 2012 and December 2013, the Optional Protocol was ratified by Cameroon, Indonesia and Nigeria, and was acceded to by Swaziland and Zimbabwe, bringing the total number of States parties to 152. To date, a total of 20 Member States have signed but not ratified the Optional Protocol. Furthermore, the Special Representative welcomes the firm pledge made in December 2013 by Mr. Hassan Sheikh Mohamud, President of the Federal Republic of Somalia, to adhere to the Convention on the Rights of the Child, and hopes that this will translate into ratification of the Convention and its Optional Protocols as soon as possible. 12