A/HRC/28/68/Add.1 punishment defined solitary confinement, in accordance with the Istanbul Statement on the Use and Effects of Solitary Confinement, as the physical and social isolation of individuals who are confined in their cells for 22 to 24 hours a day. He observed that while solitary confinement for short periods of time may be justified under certain circumstances, with adequate and effective safeguards in place, the use of prolonged or indefinite solitary confinement may never constitute a legitimate instrument of the State and it runs afoul of the absolute prohibition of torture and other cruel, inhuman or degrading treatment or punishment. Furthermore, due to the prisoner’s lack of communication, as well as the lack of witnesses inside the prison, solitary confinement may also give rise to other acts of torture or ill-treatment. 474. Being aware of the arbitrary nature of any effort to establish a moment in time when an already harsh regime becomes prolonged and therefore unacceptable, the Special Rapporteur defined that prolonged solitary confinement is any period of solitary confinement in excess of 15 days (A/66/268) under conditions of total isolation. This definition was based on the large majority of scientific studies which indicate that after 15 days of isolation harmful psychological effects often manifest and may even become irreversible. For solitary confinement that includes some mitigating factors, such as access to reading and writing materials, radio or television, the term of legitimate use of isolation may exceed 15 days but would still have to be counted in days, not weeks or months or years. The Special Rapporteur recalls that when used indefinitely or for long periods, solitary confinement amounts to cruel, inhuman or degrading treatment or punishment or even torture, because it may cause severe mental and physical pain or suffering, a point which has been reiterated in paragraph 28 of the General Assembly resolution 68/156. 475. The Special Rapporteur recalls that any form of corporal punishment constitutes cruel, inhuman or degrading punishment in violation of customary international law. An imposition of such penalty, even if not actually executed, is itself a threat of pain and suffering of a mental nature that is equally prohibited by international law. 476. In the absence of information to the contrary, the Rapporteur concludes that there is substance in the allegations presented in the initial communication, that members of ACPRA, including Mr. Sheikh Suliaman al-Rashudi, Dr. Abdullah al-Hamid, Dr. Mohammad al-Qahtani, Dr. Abdulkareem Yousef al-Khoder, Mr. Mohammed Saleh alBajadi, Mr. Omar al-Hamid al-Saeed and Dr. Abdulrahman al-Hamid have been arbitrarily detained and have been placed in solitary confinement and incommunicado detention. Thus, that the Government of Saudi Arabia, by failing to protect the physical and mental integrity of the members of ACPRA, has violated their right to be free from torture and other cruel, inhuman or degrading treatment or punishment as provided by articles 1 and 16 or the CAT. With regards to the present case, the Special Rapporteur recalls paragraph 6 of General Comment No. 20 of the Human Rights Committee as well as article 7 of the Basic Principles for the Treatment of Prisoners (Adopted by the General Assembly by resolution 45/111 of 14 December 1990). Serbia JUA 28/07/2014 Case No. SRB 1/2014 State Replies: 18/11/2014 and 11/12/2014 Allegations of attacks, threats and acts of intimidation against the non-governmental organization Women in Black and its members. 477. The Special Rapporteur thanks the Government of Serbia for its replies, dated 18.11.2014 and 11.12.2014 to the present communication. 478. The Rapporteur takes note of the information provided by the Government that the trial for Radomir Pocuca, former spokesperson of the Anti-Terrorist Unit of the Ministry of 81