A judicial official told The Associated Press that four men and one woman were arrested Tuesday in the southeastern Isere region on suspicion of taking part in a criminal terrorist association and of providing financial support to a terrorist undertaking.
Investigators believe that the five are linked to jihadis in combat zones in Syria and Iraq and are suspected of giving them money.
The official said the five will remain in custody until a judge decides on whether to file preliminary charges. He requested anonymity to speak about an ongoing investigation.
French authorities said last month that two potential extremist attacks have been thwarted in France since January.