A/HRC/44/37 prisons in Port Harcourt, Lagos and central Nigeria helped to increase public awareness regarding the conditions of detention and the high rate of pretrial detainees, constituting some 89 per cent of the population in Nigerian prisons. OHCHR facilitated the provision of pro bono legal assistance to 140 pretrial detainees following the release of the Committee’s report. 22. In 2016 and 2017, OHCHR Guatemala carried out a joint study with the national human rights institution on the issue of pretrial detention. The report is based on joint monitoring and consultations with members of the judiciary, criminal public defence actors, the Office of the Attorney General and the prison system. The study concluded with a series of recommendations, including addressing internal practices that facilitated excessive recourse to pretrial detention. In 2018, OHCHR Guatemala provided technical advice to State institutions, civil society and the Congress regarding reforms related to pretrial detention regulations in the Criminal Procedure Code. 23. Through its prison reform support programme in Cambodia, OHCHR addresses the importance of adequate accommodation as elaborated in the Mandela Rules. It has supported the General Department of Prisons to improve sanitation, hygiene and access to potable water. In 2019, the General Department of Prisons produced a final draft minimum standard on prison construction based on previous recommendations jointly provided by OHCHR and UNOPS and consolidated by ICRC. The guidelines reflect international human rights norms and standards and provide for the separation of different categories of detainees, including provision for person with disabilities and children imprisoned with their mothers. 24. Following engagement by the United Nations Human Rights Monitoring Mission in Ukraine to reduce unlawful pretrial detention in conflict-related criminal cases, the Constitutional Court of Ukraine declared article 176.5 of the Criminal Procedure Code unconstitutional in June 2019. Adopted in 2014, article 176.5 provided for automatic application and extension of pretrial detention in conflict-related criminal cases. This provision led to the excessive use of pretrial detention, and together with protracted trials had an impact on conditions of detention and the dignity of persons detained. OHCHR advocated for the law to be amended, including by submission of amicus curiae to the Constitutional Court. 25. Monitoring the situation of irregular migrants in detention, including unaccompanied and separated minors, is a critical focus of the work of OHCHR Mexico. In relation to the safeguards in detention included in the Mandela Rules, the Office presented recommendations to the Federal Congress on legislation to establish a national registry of detention and comprehensive registration of all detainees on admission to detention, in line with Nelson Mandela Rules Nos. 6–10, which led to the adoption of a national law on the registry of detention. The Office also delivered technical advice on the use of pretrial detention, which contributed to the adoption of a constitutional reform enabling a review of the use of pretrial detention by 2024. 26. During 2018, OHCHR Yemen conducted 121 visits to prisons and detention facilities, including joint visits in eight southern governorates in cooperation with the Ministry of the Interior and the Attorney General. Following coordination with the respective authorities and humanitarian agencies, the wards for juveniles and for women in the Al Hudaydah central prison were provided with a solar power system and water filters. In 2018, OHCHR conducted training for 71 officials from the Ministry of the Interior, the Office of the Attorney General and the Human Rights Ministry, on issues such as health care in prison, protection of vulnerable groups, prison administration and non-custodial measures. Following the training, the participants drafted an internal set of recommendations aimed at improving the rights of prisoners, highlighting key areas of the Mandela Rules. 27. In Uganda, OHCHR has undertaken extensive monitoring, with 202 visits to places of detention between 2015 and 2018. The Office works with the Uganda Human Rights Commission, the Justice, Law and Order Sector of the Government and the Ugandan Prison Service to improve conditions based on findings from detention monitoring. In the remote Karamoja region, joint monitoring and advocacy conducted by the Office, the Commission and other stakeholders, led to the renovation and construction of a new wing in Amita prison in Abim district and the construction of a new facility in Kaabong. Furthermore, in 2019 joint monitoring with the Joint United Nations Programme on HIV/AIDS, the Ugandan Human Rights Commission and WHO on access to health care in prisons resulted in the secondment of a ministry health worker to cover each of the prisons in the Karamoja region. 6