Exhaustive list of grounds for detention 4.4. Inappropriate use of detention to protect the child A common argument to support migration detention of unaccompanied children is that it protects children from going missing or falling prey to people traffickers. For example, in Greece, unaccompanied children are regularly held in police cells as a discretionary protective measure pending transfer to a specialised accommodation facility. In the mainland as well as in the hotspots set up on the Greek islands to register and host new arrivals, unaccompanied children are in some cases deprived of their liberty, a measure imposed to prevent exploitation and avoid children going missing.151 National law provides that unaccompanied children should not, as a rule, be detained, although it allows detention of asylum-seeking children in very exceptional cases, as a last resort, to ensure that they are safely referred to specialised accommodation facilities. The child could be detained for up to 25 days and exceptionally (e.g. in cases of mass influx) for 20 more days.152 In practice, because accommodation for unaccompanied children is limited, children have been detained in hotspots or police cells, in inadequate conditions, often for a long time.153 EU Member States sometimes place child victims of human trafficking, or other children at imminent risk, in safe houses where freedom of movement is restricted. This aims to reduce the risk of disappearances or child abduction. In its handbook on guardianship,154 FRA underlines that restrictions on the child’s freedom of movement should be: • proportionate; • based on a risk assessment; • always confirmed by judicial authorities. 151 FRA (2016), Opinion of the European Union Agency for Fundamental Rights on fundamental rights in the ‘hotspots’ set up in Greece and Italy, Luxembourg, Publications Office. 152 Article 46 (10)(b) L 4375/2016. 153 See https://www.synigoros.gr/resources/dt-asynodeytoianilikoi-3032016.pdf. 154 FRA (2014), Guardianship for children deprived of parental care – A handbook to reinforce guardianship systems to cater for the specific needs of child victims of trafficking, Luxembourg, Publications Office. When a victim is placed in a safe house where exit and entry is controlled, mitigating measures should ensure that the child is not in a detention-like regime. Such measures could include regular outings with the guardian, social workers or volunteers. The guardian should have unimpeded access to a child hosted in a closed facility and the child should have unimpeded access to the guardian and to other services. Judicial authorities should review measures restricting freedom of movements every month, to ensure that the placement is absolutely necessary for the safety of the child and is limited to the minimum time necessary.155 Conclusion The ECHR and EU law list exhaustive but not identical permissible grounds for detention, which apply to everyone regardless of age. The right to liberty and security in Article  6 of the Charter corresponds to the same right in Article 5 of the ECHR. The meaning and scope of Article 6 of the Charter must therefore not go below the standard of protection of the ECHR, as interpreted by the ECtHR. EU law may, however, provide more extensive protection (Article 52 of the Charter). The scope and content of the Charter’s right to liberty and security, as shaped by the ECtHR, thus represents a minimum threshold of protection under EU law. Most grounds for deprivation of liberty in secondary EU law correspond to those in the ECHR, but detention to protect public order under the Reception Conditions Directive seems difficult to subsume under Article 5 (1) of the ECHR. This can lead to diverging interpretations regarding the compatibility of national legislations with European law standards. 155 FRA (2014), Guardianship for children deprived of parental care – A handbook to reinforce guardianship systems to cater for the specific needs of child victims of trafficking, Luxembourg, Publications Office, pp. 78-9. 45