Nine men have appeared in court charged with a total of 41 historical sexual offences, relating to eight victims who were children at the time. Appearing at Newport Magistrates' Court, the defendants were told most charges were so serious that the cases would be transferred to Crown court. They will appear at Cardiff Crown Court on 21 August. Operation Oak has been described by the force as a "complex and long-running investigation into group-based child sexual exploitation in south Wales". No pleas were entered during the short hearings at Newport Magistrates' Court on Friday.