A/HRC/39/45 international obligation of a State under article 15 of the Convention against Torture. 21 The Working Group thus reiterates that it is mindful of measures aimed at eliminating the possibilities for the extraction of confessions through ill-treatment and torture, as these could minimize the occurrence of situations of arbitrary detention. 64. In addition, during its 2017 country visits to both Argentina and Sri Lanka, the Working Group paid special attention to the implementation of the terms of the Optional Protocol to the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment and especially to the establishment of national preventive mechanisms in those two countries. 22 Emphasizing that regular independent oversight over all places of deprivation of liberty also has a significant role to play in reducing instances of arbitrary detention, the Working Group has encouraged the respective Governments to establish national preventive mechanisms that would be comprised of entities that are fully independent of the executive, properly funded, and able to discharge their mandate effectively by having unfettered access to a wide range of places of deprivation of liberty. 65. The Working Group is liaising with the Committee against Torture, the Subcommittee on Prevention of Torture, the Special Rapporteur on torture, and the United Nations Voluntary Fund for Victims of Torture to ensure a common strategic approach to the fight against torture, thus, in turn, contributing to the eradication of instances of arbitrary detention. 66. The Working Group invites all States that have not yet done so to become parties to the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment and to give early consideration to signing and ratifying the Optional Protocol thereto as a matter of priority. The Working Group urges States to adopt, implement and fully comply with legal and procedural safeguards against torture and other cruel, inhuman or degrading treatment or punishment, as these contribute significantly to minimizing instances of arbitrary detention. The Working Group also urges States to ensure that the judiciary, and where relevant the prosecution, can be effective in ensuring compliance with such safeguards. IV. Conclusions 67. During 2017, the Working Group continued its work on addressing the large number of submissions received, including through its regular communications procedure. To that end, the adoption of opinions was set as a priority, resulting in the adoption of a total of 94 opinions, which constitutes a 35 per cent increase as compared to 2016. 68. The Working Group is also working to streamline the process for receiving and responding to requests for its action, always keeping in mind the need to work as effectively and promptly as possible and to keep all parties informed. 69. The Working Group has also been refining its follow-up procedure, which was adopted in August 2016, as well as other aspects of its ability to follow up on the recommendations made in its opinions, during country visits and in the reports it produces following such visits. 70. In this context, the Working Group welcomes the increased cooperation from States under its regular communications procedure, and the fact that the States concerned provided a timely response to the Working Group’s communications and requests for information in approximately 60 per cent of the cases in which the Working Group adopted an opinion in 2017 (see the table that starts on page 4 above). 71. The Working Group has also noticed an increased response rate in the context of its follow-up procedure, both from sources and from Governments, with responses having been received in more than 50 per cent of cases in which follow-up information 21 22 Ibid. See A/HRC/39/45/Add.1 and A/HRC/39/45/Add.2. 29