E/CN.4/1995/111 page 21 detentions, 43 were tortured in the place where they were detained, 94 in the army barracks of the Nueva Granada Battalion, 52 in the Battalion’s own installations and 21 were first tortured on military bases and then taken to the Battalion, where the torture continued. Torture was also reported to have occurred in other military and police installations in the jurisdiction" such as those of the Luciano D’Luyer and Calibio Battalions. 25/ 64. The existence of guerrilla organizations practising extortion and abduction led to the creation during the 1960s of the so-called "self-defence groups", armed and trained by the armed forces, in whose counterinsurgency campaigns they assisted. These groups are considered as the origin of the paramilitary groups that emerged in the beginning of the 1980s with the appearance of the Muerte a Secuestradores (MAS) (Death to Abductors) and that continue to operate in the region. They appear to be particularly predominant in El Carmen, San Vicente de Chucurí, Puerto Wilches and Sabana de Torres (Santander), in the rural area of San Pablo (south of Bolívar) and in the petroleum areas of El Centro in Barrancabermeja. At the end of 1993, in the surrounding area of Sabana de Torres (Santander), groups known as "motosierras" ("chainsaws") made their presence; they were so named for their use of chainsaws to mutilate the bodies of their victims. In the area of the south of Cesar (San Alberto) and the south of Bolívar (San Pablo, Simiti), some 23 paramilitary groups are said to be active, despite the strong presence of the National Army. 65. In the framework of operations against the guerrillas, the army, at times together with paramilitary groups, has engaged in intimidation, harassment, killings and, in many cases, massacres that in some regions have provoked population displacement. For example, in San Pablo, in the south of Bolívar, in 1993 there were around 50 cases of displacement of families as a result of "rastrillo" ("rake") operations of the 2nd Mobile Brigade. 66. As for the insurgent groups, they continue carrying out abductions and abuses, also against the civilian population. The ELN has been accused of placing mines ("quiebrapatas") that, specially in the rural areas of San Vicente de Chucurí, have resulted in cases of mutilation, including of children. Drug trafficking is also present in the municipalities of La Dorada, Caldas, Puerto Boyacá and Puerto Berrio. 67. It was also reported that common crime has begun to emerge as another element of violence in Barrancabermeja and its zone of influence. In the urban centres, youth gangs engaging in robbery and other crimes have been formed. C. Valle del Cauca 68. The department of Valle del Cauca, the economic, political and military centre of the south-west of Colombia, presents a complex situation of violence in rural and urban areas. With 1,138 violent deaths, the department ranks third in the statistics published by Justicia y Paz for the year 1993. The Procuradoría General de la Nación received 107 complaints in 1993, 37 per cent less than in 1992. However, during his visit to Cali, the Special Rapporteur on extrajudicial, summary or arbitrary executions was informed that the level of violence has not decreased: during the first six months of 1994,