Six people were arrested in the Paris region on Monday in coordinated raids on members of a suspected radical Islamist cell allegedly planning "terrorist acts" on French soil, a source close to the investigation told AFP.
The suspects, aged between 22 and 38, were "all known to police for serious delinquency" and are being detained by the police anti-terrorist unit in the Paris suburb of Levallois.
The members of the suspected Islamist cell include one man from Benin, another from the Comoros and four French nationals, a source close to the case said.
They are suspected of being involved in the hold-up of a branch of the Banque Postale in Seine-et-Marne in April "and apparently planning to commit other armed robberies", the source close to the investigation said.
According to the anti-terror police investigators, "they were planning to commit terrorist acts targeting well-known figures in France," the source added.
The suspects can be held for up to 96 hours before being charged or released.
Last October French police dismantled another Islamist cell, suspected of carrying out a grenade attack on a Jewish grocery store in a Paris suburb the previous month.
A French prosecutor branded that homegrown group of Islamist extremists as the biggest terror threat the country had faced since the Algerian-based GIA carried out a string of deadly bombings in the 1990s.
The suspected leader of the group, 33-year-old Jeremie Louis-Sidney, was shot dead after he opened fire on officers seeking to arrest him in a dawn raid at his home in Strasbourg.
In May, Interior Minister Manuel Valls warned of a "global terrorist threat", stressing that France was among the countries facing that threat, from both within and outside its borders.
"There is no longer a hermetic border between the interior and the exterior, the enemies within and those outside share in the global combat, to do harm to democracies in the name of radical Islamism," he said.