Five men have been detained and weapons seized in anti-terrorist operations across France, five days ahead of a tense presidential runoff.
The suspects are between 18 and 24 years old.
The prosecutor’s office says they were picked up in operations in three sites: near the Normandy city of Rouen, in northern France and in Roanne in central France.
The Paris prosecutor oversees anti-terrorism investigations.
It is not clear whether the arrests had any link to the presidential campaign.
An attack claimed by the Islamic State group killed a police officer in Paris two weeks ago.
France is under a state of emergency after a string of deadly Islamic extremist attacks.