Ten people said to have far-right links were detained in a series of raids conducted by French anti-terrorist police in the Paris and Marseille areas on Tuesday.
They reportedly intended to hit mosques, migrants and a former presidential candidate.
TV station M6 said the men, aged between 17 and 25 were arrested in Seine-Saint-Denis, north of Paris, and in the Mediterranean port city of Marseille.
A French judicial official told The Associated Press that officers investigating the militant held the people detained on Tuesday under a possible charge of criminal terrorist association.
The suspected extremist only has been identified as Logan N. He was arrested in June and given preliminary charges after intelligence agents learned of his alleged attacks. They claim he maintained a Facebook page glorifying Anders Behring Breivik, a convicted far-right Norwegian terrorist who killed 77 people.
The suspects harbored “intentions to commit violent actions”, according a judicial source, cited by AFP. No details have been given as to the nature and supposed timing of the actions.
More than 230 people have been killed in attacks by militants in France over the past three years and the country has been under a state of emergency since late 2015, following an attack on Paris in November 2015.