C. Safeguarding human rights The challenge of the refugee crisis the mainland. The Turkish side however, appeared in November 2016 to be refusing the readmission of third-country nationals who have been transferred from the islands to Pre-removal Centers of the mainland. The Government then announced closed-type centers on the islands, while similar announcements were made by the European Commission in December 2016, by invoking the increase of violations of the law in overcrowded island areas. At the same time, in 2016, public order reasons are also frequently claimed for the detention of third-country nationals on the mainland. In November 2016, the number of detainees in Pre-removal Centers increased to 1583 third-country nationals, which means that they tripled compared to the previous year. The greatest concentration of detainees was seen in the Preremoval Center of Corinth (697 detainees). 1.3. Recommendations and estimates of the Ombudsman The Ombudsman’s main recommendations pertaining to administrative detention based on the Return Directive, which were expressed before the surge of the mixed flows, but still remain current, are in summary the following: • G eneral limitation of the period of detention in view of removal to the absolute necessary time, with individualised and justified assessment of the necessity of the continuation of the detention of each third-country national, in combination with the feasibility or not of removal from the country and with the Administration’s due diligence in moving forward the removal procedure, and • Implementation of alternative measures to detention, ac- cording to Article 22(3) of Law 3907/2011, in order to render detention the exception, as stipulated by law (Article 30(1) of Law 3907/2011) and not the general rule, as it happens in practice.183 As regards the new problems that emerged in 2016, the Ombudsman also made the following estimates: • It is necessary to give specific justification of the risk to public order, according to the case law of the Supreme Administrative Court (Conseil d’ Etat), in order not to have phenomena where residual provisions of the law survive 183 The need to render detention an extraordinary measure was also noted by the UN’s special rapporteur on the rights of migrants, Mr. F. Crépeau, during his visit to Greece in May 2016. (http://www.ohchr.org/EN/NewsEvents/Pages/DisplayNews. aspx?NewsID=19972&LangID=E). 60 regarding administrative detention dating before the Return Directive. The latter has introduced the objective goal of enforcing the return as a legal basis for the detention, when it is necessary because no alternative measures can be implemented, the third-country national is at risk of absconding, etc. (see Article 30 of Law 3907/2011).184 •  he phenomenon of re-detention, a few months later, T of third-country nationals who had been released due to reaching the 18 month limit, may be considered as a violation of the maximum time limit of administrative detention, unless there are new substantial reasons,185 constituting an important change in the relevant circumstances according to the Return Handbook of the European Union (par. 14.5).186 • D etention in order to achieve readmission on the 5 is- lands where hotspots are operating after the EU-Turkey Statement, creates anew the problem of imposing detention as a general and not an individual measure, which in fact is imposed also to those voluntarily requesting their return through the IOM.187 In mid-November 2016 there were approximately 16,000 people at the hotspots, who had crossed the sea borders, a number which is nearly double the total capacity of these centers. • T he use of the tool of administrative detention for regu- lating migrant flows is however an issue of legality, considering that under the Return Directive, the measure of proportionality is judged by the necessity of the onerous restriction of liberty, in order to achieve the purpose of removal. The order in which the stages of the return procedure 184 Another phenomenon was witnessed, where third-country nationals released from penitentiary institutions were taken to administrative detention for public order reasons (case 212773/2016). The extensive administrative detention of released third-country nationals at the Pre-removal Centers “for reasons of public order” does not coincide with the non-punishing nature of administrative detention according to the case law of the ECtHR (case Saadi v. UK, 2008, App. No. 13229/03, par. 78). 185 ECtHR judgment, John v Greece, 10-5-2007, app. No. 199/05. 186 http://ec.europa.eu/dgs/home-affairs/what-we-do/policies/europeanagenda-migration/proposal-implementation-package/docs/return_handbook_ el.pdf 187 See criticism by FRA http://fra.europa.eu/en/opinion/2016/fra-opinionfundamental-rights-hotspots-set-greece-and-italy, pg. 49, opinion No. 20 «FRA Opinion 20: Under Article 6 of the Charter and Article 5 of the European Convention on Human Rights (ECHR) both enshrining the right to liberty and security, detention is a limited exception to the right to liberty and as such needs to be based on a prior individual assessment. Pre-removal detention applied without assessing the risk of absconding, particularly in relation to persons who have expressed their intention to leave the EU voluntarily may fall short of this standard and become arbitrary. Unless it is determined based on an individual assessment of the specific case that there are overriding reasons to impose detention, persons having agreed to be readmitted should not be unduly restricted in their liberty”.