A judicial official, who spoke Saturday on condition of anonymity as he was not allowed to comment publicly on the arrests, said the eight were charged for association with a terrorist network. Seven are in custody and one is under judicial supervision.
Ten people suspected of using encrypted social networks to prepare a possible attack were arrested Tuesday during operations in France and Switzerland aimed at clarifying details of an alleged plot.
The suspects are being questioned following searches of properties in the Paris suburbs and in southeastern France. Officials say some of the suspects previously had been flagged for alleged Islamic radicalisation.