E/CN.4/1991/17 page 52 alleged that prisoners suspected of supporting the SPLA had been tortured while detained at army barracks. It was further alleged that more than 40 people arrested in November and December 1989 were tortured by members of the security service while being detained in safe houses and interrogation centres in Khartoum. 158. On 20 April 1990 the Special Rapporteur sent an urgent appeal to the Government of Sudan concerning the former Prime Minister, Mr. Sadiq Al Mahdi. It was reported that following his release from Kober prison he was now under house arrest in Al-Riyadh suburb, Khartoum. It was alleged that on 13 April 1990 the house was put under heavy military guard, Mr. Sadiq Al Mahdi's family was ordered to evacuate the house and he was confined to one closed room. It was further alleged that Mr. Sadiq Al Mahdi, who was reportedly in poor health, suffering in particular from serious eye problems, was not allowed to receive visits by his opthalmologist and was being denied medicine, such as analgesics and tranquillizers. He was also allegedly denied food. 159. On 1 May 1990 the Special Rapporteur sent an urgent appeal to the Government of Sudan concerning Alfred Taban, a journalist, who was arrested in Khartoum on 31 March 1980, and has reportedly been held incommunicado, without charge, since that date. Fears have been expressed that he may be tortured while in detention. 160. On 7 May 1990 the Special Rapporteur sent an urgent appeal to the Government of Sudan concerning Abderrahman Farah, a former security adviser who was arrested in late March 1990 for alleged conspiracy to overthrow the Government. It was reported that after his arrest he was detained at Jabal Awliya barracks, but was later taken to a secret detention centre in Khartoum, reportedly located at the former office of the national elections committee. It was alleged that Mr. Farah had been tortured and severely beaten, as a result of which he suffered a serious internal haemorrhage. He was reported to be in a very critical condition. 161. On 15 June 1990 the Special Rapporteur sent an urgent appeal to the Government of Sudan concerning a group of over 20 people who were arrested in Khartoum in early and mid-May 1990 and have since been held incommunicado. Those detained reportedly included former ministers and parliamentarians, university lecturers and medical doctors, most of whom were said to be members of the Umma Party and supporters of the Democratic Alliance. The names of 10 of these persons were reported as following: Abu Zeid Mohamed Saleh, Dr. Bashir Omar, Babiker Digna, Ali Al-'Omda, Mekki Al-Massiba, Dr. Farah Hassan Adam, Dr. 'Abdin Mohamed Zein Al-'Abdin, Dr. Salma Shwaya, Fatma Al-Ginayed, and Dr. Osama Abderrahmane Al-Nur. Information was also received on conditions prevailing in the prison of Shallah, in Dafur Region, where 71 persons, including politicians, trade unionists, lawyers and members of other professional groups, were said to be held incommunicado for several months. It was alleged that the prison was situated in a desert area 1,600 km from Khartoum and that all the detainees were kept in two medium-sized wards. It was further alleged that the quality of food and water was very poor, sanitary conditions were insufficient and medical assistance was unavailable.