- 56 From the information gathered by the CPT and its delegation, it appears that Corinth Preremoval Centre and Thessaloniki Special holding facility for irregular migrants are currently being used by the Greek authorities to hold unaccompanied children under “protective custody”. Moreover, it seems that shortly after the end-of-visit talks, during which the delegation welcomed the fact that Amygdaleza Special holding facility for unaccompanied children stopped operating in December 2016, the facility has been re-opened, despite the CPT’s previous recommendation to no longer use the establishment for detaining unaccompanied children. The CPT would like to receive the Greek authorities’ comments in this respect. 127. The delegation also met two unaccompanied children at Feres Police and Border Guard Station. The children had been held there for two weeks under “protective custody”. While they were held separately in one cell, they were able to walk almost without restriction in the corridor of the detention area (the cells of the other detainees being locked). Despite this arrangement, conditions of detention were totally inadequate for holding unaccompanied children, as they were provided with no activities or psycho-social support. From the information provided by the Greek authorities to the delegation, it became clear that unaccompanied children were also held at Doirani and Mygdonia Police and Border Guard Stations. In its report on the 2016 visits, the CPT had already underlined that placing unaccompanied children for several days or even weeks in police custody for “protection” purposes without any assistance or psycho-social support is unacceptable; the children’s welfare, by definition, should exclude accommodating them in police and border guard stations. 128. The Committee has repeatedly stressed that every effort should be made to avoid resorting to immigration detention of migrant children. In particular, as a matter of principle, unaccompanied children should not be held in a closed immigration detention facility, but they should always be provided with special care and accommodated in an open (or semi-open) establishment specialised for juveniles (e.g. a social welfare/educational institution for juveniles). In the light of the above, the CPT recommends that the Greek authorities fundamentally revise their policy regarding the detention of unaccompanied children both for reception and identification purposes and under “protective custody” in places of deprivation of liberty – be it in RICs, pre-removal centres, special holding facilities for irregular migrants or police and border guard stations – in line with the principle of the best interests of the child. As a matter of priority, an end should be put to holding unaccompanied children in these establishments. Instead, they should be transferred without delay to a (semi-) open establishment specialised for juveniles (e.g. a social welfare/educational institution for juveniles). 129. In the course of the April 2018 visit, the delegation again met a number of foreign nationals in the pre-removal centres at Moria and Pyli who claimed that they were unaccompanied minors but that they had been registered as adults. Two of them were able to show a copy of their birth certificates, which clearly proved that they were younger than 18 years. Despite these documents in their possession, they remained detained together with adults at Moria. In this context, the CPT notes that there is still no reliable system of age assessment in place for persons held by the police. A number of minors also appeared to have problems in proving their age, as the prosecutorial and judicial authorities would only accept original and/or officially translated documents.