Detention of unaccompanied children
In theory, unaccompanied children cannot be returned and therefore cannot be detained as a consequence. Nevertheless, it is important to stress that in 2019, the six NGOs working in administrative detention centres met 264 detained persons who declared themselves to be children. These were young persons whose age had been disputed by the authorities and had been considered as adults, as a result of a medical examination for instance. 60% of these young persons were released after a judicial decision and 19% after an administrative decision in 2019. More recent statistics on the year 2020 are not available.
As regards waiting zones, unaccompanied children, generally speaking, are often maintained in waiting zones in inadequate conditions. The Ombudsman urged in 2017 for a better consideration of their interests, in particular by: consolidating training of agents working in waiting zones; informing children about their situation and rights; providing them more space to speak and to be heard; establishing separate spaces for children in the waiting zone; and informing the Prosecutor (Procureur de la République) of all unaccompanied children in these locations. For more information on whether children can be held in these locations, see the section Border procedure (border and transit zones).
Detention of families with children
There has been a steady increase in detained families with children from 2013 to 2019. In 2020, the Public Defender of Rights reported that the widespread use of immigration detention of children with families, and instances of keeping the child in pre-removal detention alone while the parents are not held (particularly in Mayotte), remained problematic issues. 
In 2019, 6 NGOs reported that the detention of children continued to increase as 3,380 children were detained, of which 279 on mainland (136 families) and 3,101 (92%) in Mayotte.  In overseas territory, the authorities unlawfully “attach” children to unrelated adults. The Public Defender of Rights expressed concerns about persistent practices in the overseas department of Mayotte, where migrant children are falsely associated with other persons with whom they have no family ties in order for them to be placed in pre-removal detention and subsequently removed from the country. This mainly affects children from the Comoros arriving in Mayotte on makeshift crafts.  On 25 June 2020, the ECtHR condemned France about a situation that take place in 2013. Two children had been arbitrarily associated with an unrelated adult in respect of their return order, and were also detained in the same location and conditions as other adults. Moreover, it was apparent that no administrative detention order had been issued to the children, but it was made in conjunction with the same adult. As a result, the Court held, inter alia, that the children had effectively entered a legal vacuum without the possibility to challenge their removal and without the accompaniment of an adult able to legally act on their behalf.
On 12 July 2016, the ECtHR condemned France on five occasions for detaining children. In these decisions, the Court recalled that the detention of minors must be used as a last resort.
In May 2020, some deputies filled a proposal for a law (not debated to date) aiming to “strictly regulate the administrative detention of families with minors”. The National Consultative Commission on Human Rights criticised in an opinion the “proposed law to strictly regulate the administrative detention of families with children”. The draft does not categorically prohibit immigration detention of children; it merely limits such detention to 48 hours, with a possible extension of three days. Recalling that the ECtHR found France guilty of arbitrary detention on multiple occasions, the opinion calls on the National Assembly to amend the legislative proposal.
Detention of victims of trafficking
Another issue is raised in relation to victims of human trafficking. Detention places are not meant to guarantee protection and the police officers hearing third-country nationals in these centres mainly focus on their administrative status. Potential asylum-seeking victims of trafficking do not feel safe and confident to submit an asylum claim, or to express their fear and their situation. They encounter difficulties to trust police officers unable to protect them against their traffickers.
 ECtHR, Moustahi v France, Application No. 9347/14. 25 June 2020.
 ECtHR, A.B. v. France, Application No 11593/12, R.M. and M.M. v. France, Application No 33201/11, A.M. v. France, Application No 24587/12, R.K. v. France, Application No 68264/14 and R.C. v. France, Application No 76491/14, Judgments of 12 July 2016.
 CNCDH, ‘Avis sur la proposition de loi visant à encadrer strictement la rétention administrative des familles avec mineurs : une occasion manquée’, NOR : CDHX2025771V, 4 October 2020, available in French at : https://bit.ly/2NlCTmg.