French police have arrested eight men suspected of recruiting fighters for Islamist militants in Syria, Interior Minister Barnard Cazeneuve said.
The arrests in the Paris and Lyon areas are not linked to the Charlie Hebdo attacks in January, Mr Cazeneuve told local media.
France remains on alert after 17 people were killed in attacks on the satirical magazine and a Jewish supermarket.
Under French law, the suspects can be held for up to 96 hours without charge.
Speaking at a press conference, Mr Cazeneuve said the eight men had actively participated in a network recruiting French youths for jihad in Syria.
"The battle against terrorism is also a race against time," he said. "Our determination is total."
The French government estimates that around 400 French citizens have travelled to Syria and Iraq to fight alongside militants, and that there are approximately 900 more at home with links to recruitment cells.
Mr Cazeneuve said 161 terror-related legal proceedings were in progress, with 547 individuals suspected of involvement in terror networks.
The arrests on Tuesday follow a similar raid a week ago in southern France, when five men were detained in the small town of Lunel on suspicion of belonging to a jihadist cell.
A raft of new security measures were introduced in the wake of the Paris attacks.
More than 10,000 troops were deployed across France to protect public spaces, schools, synagogues and mosques.
Similar measures were introduced in Belgium in January after a major anti-terror raid in the city of Verviers in which two suspected Islamist militants were killed.
Belgian officials said the suspects had returned from Syria and were planning imminent attacks on police targets.