A/HRC/13/39/Add.4 25. Several detainees indicated that violence among prisoners in both Bata and Black Beach Prisons was common and tacitly tolerated by the prison authorities. The Special Rapporteur also received reports about discriminatory practices against foreigners and sometimes against the minority Bubi ethnic group by other detainees and by the prison staff. In addition, he was informed that sexual violence and harassment of women and minors was common. 26. The high-security unit in Black Beach Prison was newly renovated and the physical conditions were of a high standard (the cells measured about 3,5 x 2,5 meters, contained a shower, toilet and sink, which were separated by a low wall, a bed, chair and fan, and all the prisoners were allowed to have some private items). However, some of the persons suspected or convicted of political crimes had been held in solitary confinement for prolonged periods of up to four years. As the Special Rapporteur has observed in his last report to the GA "the use of solitary confinement should be kept to a minimum, used in very exceptional cases, for as short a time as possible, and only as a last resort."4 Moreover, with the exception of Simon Mann, who seemed to receive privileged treatment, the highsecurity prisoners were not allowed the one hour of exercise per day required by the Standard Minimum Rules for the Treatment of Prisoners (paragraph 21) and held in leg irons practically all the time. In the Special Rapporteur’s assessment, the permanent use of leg irons amounts to inhuman treatment. 27. Bata Prison laudably applied a very liberal visiting policy: the Special Rapporteur received no allegations about any restrictions on visits during visiting hours. On the other hand, in Black Beach Prison, family visits appeared to be generally forbidden (except for a limited number of privileged prisoners). Many of the interviewed detainees indicated that they suffered from the fact that they could never see their families. Another concern was that no policy seemed to be in place authorizing children, even those of a young age, to see their detained parents. Several women told the Special Rapporteur that they had not seen their children for many months, which they found unbearable. Contact with the outside world is a major component of successful rehabilitation and reintegration of detainees and is required by article 10 of the International Covenant on Civil and Political Rights. Paragraph 37 of the Standard Minimum Rules for the Treatment of Prisoners provide that “Prisoners shall be allowed under necessary supervision to communicate with their family and reputable friends at regular intervals, both by correspondence and by receiving visits.” 28. Some overcrowding was reported to the Special Rapporteur: for instance, in the wing for petty offenders in Black Beach, there were only 24 mattresses for about 40 detainees who were present during the visit of the Special Rapporteur. In Bata prison, reportedly more than 70 prisoners were at times kept in the cell, so that three persons had to share one bed. Several small, dirty and humid punishment cells, not suitable for detention, were located on one side of the large courtyard. On the day of the visit, two persons were there because they had tried to escape. Iron rings were cemented into the walls at about 25 4 10 See Report of the Special Rapporteur on Torture to the UN General Assembly, 28 July 2008, UN Doc. A/63/175, paras 82-83, where he also stated: "“The weight of accumulated evidence to date points to the serious and adverse health effects of the use of solitary confinement: from insomnia and confusion to hallucinations and mental illness. The key adverse factor of solitary confinement is that socially and psychologically meaningful contact is reduced to the absolute minimum, to a point that is insufficient for most detainees to remain mentally well functioning. […] In the opinion of the Special Rapporteur, the use of solitary confinement should be kept to a minimum, used in very exceptional cases, for as short a time as possible, and only as a last resort. Regardless of the specific circumstances of its use, effort is required to raise the level of social contacts for prisoners: prisonerprison staff contact, allowing access to social activities with other prisoners, allowing more visits and providing access to mental health services.”