CAT/C/SWE/CO/6-7 limitations are not always only for the shortest possible time; (c) the use of detention is, in practice, much more common than supervision; and (d) some asylum seekers are still placed in remand prisons for security or other exceptional reasons (arts. 11 and 16). The State party should take all necessary measures to ensure that the detention of asylum seekers is used only as a last resort and, where necessary, for as short a period as possible and without excessive restrictions. The Committee recommends that the State party reviews the law and practice in relation to the exceptionally lengthy detention of asylum seekers and in order to improve the capacity of the detention centres run by the Migration Board, with a view to avoiding the placement of asylum seekers in remand prisons. Non-refoulement 11. The Committee welcomes the positive developments in this matter, including the permanent residence permits granted to Mr. Agiza in July 2012 and Mr. Alzery in April 2014 and the legal position issued by the Migration Board, with a view to improving investigation skills for cases of torture victims, in line with the judgement of the European Court of Human Rights in the case of R.C. v. Sweden (application No. 41827/07). The Committee also notes that all asylum seekers, including those from Iraq, are individually considered and that diplomatic assurances are considered only in exceptional cases. However, the Committee remains concerned at: (arts. 3 and 10) (a) Reports that returns to some countries have not always taken into account the risks facing individuals due to their ethnicity or religion; (b) The lack of clear guidelines on identification and proper documentation of torture victims and investigation in such cases; (c) Gaps in policy and obstacles to family reunification, including strict requirements for identity document requirements; (d) The high number of asylum seekers returned “voluntarily” or “nonvoluntarily” to Iraq. The State party should respect, in law and in practice, its non-refoulement obligations under article 3 of the Convention, inter alia, by: (a) Undertaking a judicial review of all decisions of deportation of all persons, with particular attention paid to the risks faced due to ethnicity or religion; (b) Establishing clear guidelines and related training on the investigation and documentation of torture and the identification of torture victims among asylum seekers; (c) Reviewing the criteria and procedural requirements pertaining to family reunification; (d) Refraining from the use of diplomatic assurances as a means of returning a person to another country where the person would face a risk of torture. Unaccompanied children 12. The Committee welcomes the Common Action Plan developed by the Border Control Police in Stockholm, with a view to minimizing the risk of unaccompanied children becoming victims of trafficking. However, the Committee remains concerned at the vulnerable situation of unaccompanied asylum-seeking minors and the children of irregular immigrants or undocumented children (art. 16). 4