Three women arrested after a car loaded with gas cylinders was found near Notre Dame cathedral had been planning to attack a Paris railway station, the French interior ministry said.
The Peugeot 607 was found early on Sunday laden with seven gas cylinders and three jerry cans of diesel, said police, although no detonators were discovered.
"A group has been neutralized. Others are out there," French President Francois Hollande said on the sidelines of a summit of southern European states in Athens on Friday.
The car's discovery triggered a terrorism investigation and revived fears about further attacks in a country where Islamist militants have killed more than 230 people since January, 2015.
One of the women stabbed a police officer during her arrest before being shot and wounded, Interior Minister Bernard Cazeneuve said late on Thursday.
"These three women aged 39, 23 and 19 had been radicalized, were fanatics and were in all likelihood preparing an imminent, violent act," Cazeneuve said in a televised statement.
Women tend to be involved in such attacks less frequently than men but terrorism experts say women should still be seen as "a crucial part of the terror ecosystem either as jihadis and insurgents or enablers, and efforts at counterterrorism need to take that into account," the Christian Science Monitor's Anna Mulrine reported in June:
After all, the very first person ever tried for being a terrorist, back in 1882, was a woman, notes Mia Bloom, professor of communication at Georgia State University.
Since then, women have been leaders in a number of violent extremist and revolutionary organizations, including the Baader-Meinhoff Brigade in Germany and the Revolutionary Armed Forces of Colombia, known as FARC, which is 30 to 40 percent women, as is Peru's Shining Path. The leader of the Basque armed separatist movement in Spain is currently a woman.
In France, TV footage showed a policeman leaving the scene of the arrests in the Boussy-Saint-Antoine suburb, some 30 km (20 miles) southeast of Paris, carrying a large knife.
Scores of radicalized people of French and other nationalities are in Syria and Iraq fighting for Islamic State. Many of those involved in recent attacks in France have either taken part in the fighting or had plans to.
France is among the countries bombing Islamic State strongholds, and the group has urged supporters to launch more attacks on French soil.
The Interior Ministry said all train stations had been put on alert but that the intended target had been the Gare de Lyon, a mainline train station less than 3 km (two miles) from Notre Dame in central Paris.
The Interior Ministry official said the youngest of the three women, a 19 year-old whose father owned the car, was already suspected by police of wanting to wage jihad for Islamic State in Syria. She had written a letter pledging allegiance to the militant Islamist group, the official said.
The car's owner was taken into custody earlier this week but later released. He had gone to police on Sunday to report that his daughter had disappeared with his car, officials said.
Four people were detained earlier in the week, and another man, the fiance of the 23 year-old woman, has also since been arrested, police sources said.
The newly arrested man has a connection to another attack in which a police couple was killed near Paris in June, the sources said, identifying him as the brother of a friend of the police killer, Larossi Abballa. (Additional reporting by Marine Pennetier, Matthias Blamont; Writing by Andrew Callus; Editing by Jon Boyle)