Introduction Since 2016, various EU  Member States have been attempting to speed up asylum processing and to make returns more effective. Such efforts are likely to prompt an increase in the use of detention, including to prevent absconding – possibly also affecting children. This report takes a closer look at detention of third-country national children for migration management or asylum purposes – referred to as ‘immigration detention’. The report covers unaccompanied children – children who are not accompanied by their parents or a primary caregiver – and children who are detained together with their parents. A child is any person under the age of 18 years. The report does not address detention for criminal offences. Detention and deprivation of liberty are used as synonyms throughout the report. They describe any form of confinement of a person within a particular place. They encompass all forms of deprivation of liberty of non-EU nationals on immigration-related grounds, regardless of what these measures are termed under national law. This includes, for example, the French retention or the “restriction of liberty” in hotspots on the Greek islands under Article 14 (2) of Law 4375/2016. The report presents the European and international legal framework on immigration detention of children. It gives an overview of such detention in the EU, highlighting practices of unlawful and arbitrary detention. The report also presents opinions and promising practices to assist those involved in the implementation of asylum and immigration policies, with the ultimate aim of ensuring that immigration detention of children ends completely or is truly only applied in exceptional circumstances. This report is structured in eight chapters. After introducing the right to liberty and security, it examines five sets of fundamental rights safeguards to prevent unlawful and arbitrary detention. It ends with a chapter on oversight. Figure 1 illustrates the report’s structure. The report builds on previous FRA work on Separated, asylum-seeking children in European Union Member States (2010), Detention of third-country nationals in return procedures (2010), the Handbook on Guardianship for children deprived of parental care (2014) and its comparative report (2015). Figure 1: Overview of the report’s structure Right of the child to protection and care (Chapter 1) Right to liberty and security (Chapter 2) Fundamental rights safeguards Clear legal basis in national law (Chapter 3) Based on allowed grounds (Chapter 4) Necessary and proportionate (Chapter 5) Respects procedural safeguards (Chapter 6) Conditions are humane and dignified (Chapter 7) Oversight mechanisms (Chapter 8) Source: FRA, 2017 11