PART I General principles Article 1 The objective of the present Protocol is to establish a system of regular visits undertaken by independent international and national bodies to places where people are deprived of their liberty, in order to prevent torture and other cruel, inhuman or degrading treatment or punishment. Article 2 1. A Subcommittee on Prevention of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment of the Committee against Torture (hereinafter referred to as the Subcommittee on Prevention) shall be established and shall carry out the functions laid down in the present Protocol. 2. The Subcommittee on Prevention shall carry out its work within the framework of the Charter of the United Nations and shall be guided by the purposes and principles thereof, as well as the norms of the United Nations concerning the treatment of people deprived of their liberty. 3. Equally, the Subcommittee on Prevention shall be guided by the principles of confidentiality, impartiality, non-selectivity, universality and objectivity. 4. The Subcommittee on Prevention and the States Parties shall cooperate in the implementation of the present Protocol. Article 3 Each State Party shall set up, designate or maintain at the domestic level one or several visiting bodies for the prevention of torture and other cruel, inhuman or degrading treatment or punishment (hereinafter referred to as the national preventive mechanism). Article 4 1. Each State Party shall allow visits, in accordance with the present Protocol, by the mechanisms referred to in articles 2 and 3 to any place under its jurisdiction and control where persons are or may be deprived of their liberty, either by virtue of an order given by a public authority or at its instigation or with its consent or acquiescence (hereinafter referred to as places of detention). These visits shall be undertaken with a view to strengthening, if necessary, the protection of these persons against torture and other cruel, inhuman or degrading treatment or punishment. 2. For the purposes of the present Protocol, deprivation of liberty means any form of detention or imprisonment or the placement of a person in a public or private custodial setting which that person is not permitted to leave at will by order of any judicial, administrative or other authority 46