prolonged periods and face torture or cruel, inhuman or degrading treatment. The Committee considers the “no comment” policy of the State party regarding the existence of such secret detention facilities, as well as on its intelligence activities, to be regrettable (arts. 2 and 16). The State party should ensure that no one is detained in any secret detention facility under its de facto effective control. Detaining persons in such conditions constitutes, per se, a violation of the Convention. The State party should investigate and disclose the existence of any such facilities and the authority under which they have been established and the manner in which detainees are treated. The State party should publicly condemn any policy of secret detention. The Committee recalls that intelligence activities, notwithstanding their author, nature or location, are acts of the State party, fully engaging its international responsibility. (18) The Committee is concerned by reports of the involvement of the State party in enforced disappearances. The Committee considers the State party’s view that such acts do not constitute a form of torture to be regrettable (arts. 2 and 16). The State party should adopt all necessary measures to prohibit and prevent enforced disappearance in any territory under its jurisdiction, and prosecute and punish perpetrators, as this practice constitutes, per se, a violation of the Convention. (19) Notwithstanding the State party’s statement that “[u]nder U.S. law, there is no derogation from the express statutory prohibition of torture” and that “[n]o circumstances whatsoever … may be invoked as a justification or defense to committing torture”, the Committee remains concerned at the absence of clear legal provisions ensuring that the Convention’s prohibition against torture is not derogated from under any circumstances, in particular since 11 September 2001 (arts. 2, 11 and 12). The State party should adopt clear legal provisions to implement the principle of absolute prohibition of torture in its domestic law without any possible derogation. Derogation from this principle is incompatible with paragraph 2 of article 2 of the Convention, and cannot limit criminal responsibility. The State party should also ensure that perpetrators of acts of torture are prosecuted and punished appropriately. The State party should also ensure that any interrogation rules, instructions or methods do not derogate from the principle of absolute prohibition of torture and that no doctrine under domestic law impedes the full criminal responsibility of perpetrators of acts of torture. The State party should promptly, thoroughly, and impartially investigate any responsibility of senior military and civilian officials authorizing, acquiescing or consenting, in any way, to acts of torture committed by their subordinates. (20) The Committee is concerned that the State party considers that the non-refoulement obligation, under article 3 of the Convention, does not extend to a person detained outside its territory. The Committee is also concerned by the State party’s rendition of suspects, without any judicial procedure, to States where they face a real risk of torture (art. 3). The State party should apply the non-refoulement guarantee to all detainees in its custody, cease the rendition of suspects, in particular by its intelligence agencies, to States where they face a real risk of torture, in order to comply with its obligations under article 3 of the Convention. The State party should always ensure that suspects have the possibility to challenge decisions of refoulement. 70