CAT/C/MEX/CO/5-6 residing in treatment centres and on those centres’ occupation rates. It also regrets that information is lacking on the number of minors arrested in the course of federal operations to combat organized crime and the status of those who have committed federal offences (art. 11). The Committee urges the State party to: (a) Approve the Federal Justice for Adolescents Act; (b) Carry forward the establishment of a comprehensive juvenile justice system at all levels in cooperation, inter alia, with the United Nations Children’s Fund (UNICEF); (c) Use measures involving the deprivation of liberty only as a last resort and for the least amount of time possible and review such measures regularly with a view to their discontinuation; (d) Compile statistics, disaggregated by sex, age and ethnic origin or nationality, on the number of minors, both at the federal and the state levels, who have been arrested, the reasons for their arrest and the duration of their detention. Administrative detention of asylum seekers and undocumented migrants 21. The Committee is concerned by reports of torture and disappearances of migrants present in the territory of the State party. It is also concerned by reports of ill-treatment, overcrowding and substandard conditions of detention in many of the State party’s migrant holding centres, where there is a lack of hygiene and insufficient medical care and where men and women are not always held in separate facilities at all times. The Committee notes that effective mechanisms are not in place for the identification and referral of trafficking victims who may be held in these centres. While it applauds the recent promulgation of the Refugees and Supplementary Protection Act and the Migration Act, the Committee regrets that it has not been furnished with detailed statistics on the number of refugees, asylum seekers and other non-citizens in the State party. It also regrets that the data that have been provided on applications for asylum do not correspond to the reporting period and do not include information on the number of persons who have been returned, extradited or expelled (arts. 2, 3, 11 and 16). The State party should: (a) Ensure that thorough investigations are carried out into cases involving acts of torture, including disappearances and ill-treatment of refugees, asylum seekers and other foreigners housed in the territory of the State party; (b) Improve conditions of detention in migrant holding centres. The Committee also recommends that, in order to fulfil its obligations under article 3 of the Convention, the State party should: (a) Adopt, without delay, effective measures to ensure that all foreigners within its jurisdiction are treated fairly and have genuine access to legal assistance at all stages of the corresponding procedures; (b) Expand upon existing identification and referral mechanisms, in cooperation with the Office of the United Nations High Commissioner for Refugees (UNHCR), in order to provide the requisite protection and assistance and to optimize inter-agency coordination; (c) Set up an effective system for the compilation of data on the status of refugees, asylum seekers and stateless persons present in its territory; GE.12-48654 9