CRC/C/CHN/CO/3-4 (b) Ensure that children arrested and deprived of their liberty are brought before an independent judicial authority to examine the legality of their arrest and detention within 24 hours of their arrest, are provided with adequate free and independent legal assistance immediately and can contact their parents or close relatives; (c) Independently investigate and publicly report on the existence of secret detention facilities, such as black jails, including the authority under which they have been established, and prosecute individuals responsible for operating secret detention facilities, including black jails, as well as those involved in torture and ill-treatment of children in such facilities; (d) Adopt urgent and specific measures to address the disproportionate representation of children of migrant workers in the criminal justice system; (e) Ensure that children can exercise their right to legal aid directly, and address disparities in access to justice by enhancing the quality and accessibility of legal aid to all children, including those in situations of vulnerability, such as children of migrant workers and ethnic minorities and children from religious communities. 94. The Committee recommends that Hong Kong, China: (a) Raise the minimum age of criminal responsibility to an internationally acceptable level; (b) Ensure that detention, including pretrial detention, is used as a measure of last resort and for the shortest possible period of time, even in cases of very severe crimes, and that it is reviewed on a regular basis with a view to its withdrawal; (c) Promote alternative measures to detention, such as diversion, probation, counselling, community service or suspended sentences, wherever possible, and develop social reintegration programmes for children in conflict with the law; (d) Ensure immediate removal of children from adult detention facilities and place them in a safe, child-sensitive environment where they are treated humanely and with respect for their inherent dignity, can maintain regular contact with their families, and are provided with education and vocational training. 95. The Committee urges Macao, China to prohibit and abolish the use of solitary confinement to punish children and immediately remove all children held in solitary confinement. Protection of witnesses and victims of crimes 96. The Committee regrets that the efforts to ensure measures to protect child victims and witnesses are insufficient and not properly reflected in the State party’s legislation. 97. The Committee recommends that the State party ensure, through adequate legal provisions and regulations, that all child victims and/or witnesses of crimes, for example child victims of abuse, domestic violence, sexual and economic exploitation, abduction and trafficking, and witnesses of such crimes, are provided with the protection required by the Convention, and that it take fully into account the Guidelines on Justice in Matters involving Child Victims and Witnesses of Crime. I. Ratification of international human rights instruments 98. The Committee recommends that the State party, in order to further strengthen the fulfilment of children’s rights, ratify the core human rights instruments to which it is not yet a party, particularly the Optional Protocol to the 22