The primary contact for safety issues is the police (phone number 110). The youth welfare department can be found at:
Youth Welfare offices in Rheinland-Pfalz: https://kita.rlp.de/fileadmin/kita/01_Themen/01_Wir_ueber_uns/Jugendaemter_rlp.pdf
Child protection services Rheinland-Pfalz: https://kinderrechte.rlp.de/fileadmin/MFFJIV/Familie/Kinderschutzdienste_KSD_mit_Traeger_-_Stand_November_2017_KS.pdf