The Paris prosecutor has said the three women arrested after a car loaded with gas cylinders was found near Notre Dame cathedral were directed by self-proclaimed Islamic State militants in Syria.
Francois Mollins also said that the three women were completely committed to the IS cause.
The three, aged 39, 23 and 19, were arrested in Boussy-Saint-Antoine, some 30km southeast of Paris last night.
A policeman was stabbed during the operation to arrest the women.
Mr Mollins also said one of the women was linked to the jihadists who killed a police couple and a priest in June and July.
She was the girlfriend of Larossi Abballa, who killed the police couple at their Paris suburb home in June before himself being shot dead, and then that of Adel Kermiche, who slit the throat of an elderly priest in July and was also killed by police
The discovery on Saturday night of the Peugeot 607 loaded with seven gas cylinders, six of them full, prompted a counter-terrorism investigation in a country where militants have killed more than 230 people in attacks since January 2015.
Police sources said no detonator had been found, though the vehicle also contained three jerry cans of diesel fuel, adding to concerns that there had been a plan to explode the car.