a) Investigations on any matter referred to the Committee. b) Investigations initiated by the Committee. B) INITIATIVE AND COMPOSITION OF INVESTIGATION MISSIONS Article 4: Initiative of Investigation Missions 1. Investigative missions shall be undertaken on the initiative of the Committee, under the relevant provisions of the African Charter and its Rules of Procedure, on the basis of a communication admitted by the Committee indicating serious and systematic violations of the rights of the child in a State party. 2. The Committee may also undertake an investigative mission at the invitation of the State party concerned. Any invitation from a State party to undertake an investigative mission shall be considered by the Committee without delay. 3. In the event of refusal by a State party of an investigative mission on its territory, the State concerned should indicate the reasons for this refusal in a reasonable time. The Committee shall take note and report to the Assembly of the Union, which shall then decide on further action to be taken. States parties shall strive to adopt a policy of admitting investigative missions to their territories. Article 5: Composition of investigation missions 1. On the basis of Article 62 of its Rules of Procedure, the Committee could, de- pending on the case: - set up sub-committees and/or ad hoc working groups in order to prepare for the investigations as per the provisions of Article 45 of the Charter and these directives; - designate a Head of mission to lead a mission; - designate a special Rapporteur from among its members to investigate in accordance with the above mentioned provisions; - designate independent experts to back the sub-committees, ad-hoc working groups and special rapporteurs in their missions. 3