A/HRC/36/33 than 12 homes and public buildings, including a school, a mosque and a health facility. The United States acknowledged that civilians had “likely” been killed in the raid.45 B. Arbitrary or illegal detention and violations of due process 61. Since March 2015, OHCHR has documented 1,019 cases of arbitrary or illegal detention.46 Of those, 82 per cent were attributed to Houthi/Saleh forces and their affiliates, and 15 per cent to pro-Government forces, with the remainder of cases being abductions attributed to extremist groups such as Al-Qaida and the so-called “Islamic State”. Throughout the conflict, OHCHR documented 51 cases that may amount to enforced disappearances, with the whereabouts of the victims still unknown. 62. OHCHR has conducted approximately 150 monitoring visits to detention facilities since March 2015. Conditions of detention had notably deteriorated; overcrowding, damaged facilities and shortages of food and medicines had all been exacerbated by the conflict. OHCHR was rarely able to access persons who were arbitrarily or illegally detained; it relied on interviews with released detainees, family members and lawyers, as well as information from authorities. In all the cases classified as arbitrary or illegal detention by OHCHR, the detainees had not been charged, did not have access to legal assistance and had not been brought before a court. Often, they were held in unofficial or secret facilities and prevented from contact with their families. In extreme cases, detainees appeared to have been subjected to torture or ill-treatment. 63. Since September 2014, the de facto authorities in Sana’a, affiliated with Houthi/Saleh forces, have engaged in widespread detention of individuals. Those perceived to be opposed to the de facto authorities — including political figures, activists, human rights defenders, journalists or private individuals — had been particularly targeted. Most detainees were held for several days, weeks or months before being released. Some remain detained indefinitely. 64. In addition to targeting individual opponents, the de facto authorities used mass detentions to instil fear among the wider population. Since July 2016, OHCHR has documented at least nine cases of mass detentions, in which more than ten individuals, including men, women and children, were taken in one operation. Most of them were held for a few days, then released.47 65. OHCHR monitored two trials of opponents in Sana’a by the de facto authorities that raised serious due process concerns. On 12 April 2017, a journalist was convicted and sentenced to death on charges of spying. He was not notified in advance of the trial and was not permitted to offer a defence. The trial lasted 15 minutes. In the second case, 36 individuals were accused in a mass trial, reportedly on terrorism charges. In open court, the detainees raised challenges about the use of video confessions, claiming that they were coerced and fabricated. As of June 2017, the procedure was ongoing. 66. Another development of concern was the preventive detention of migrants by the de facto authorities. According to the International Organization for Migration, in the past year, authorities in several governorates had begun to systematically detain migrants, invoking the security implications of high numbers of migrants, and for military recruitment. OHCHR had also observed this practice during visits to detention centres. 67. In the government-controlled south of the country, the official prisons had been significantly damaged and the criminal justice system remained largely defunct. Criminal justice was localized in the hands of militias, security actors and local authorities. In that context, OHCHR received numerous reports of arbitrary detention, possible enforced disappearances and torture. In 2017, allegations were mounted against both the Hadrami Elite Forces, in Hadramaut Governorate, and the Security Belt, in Aden, both Yemeni 45 46 47 See www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/1068267/us-centralcommand-statement-on-yemen-raid/. See annex III. See annex I. 13