French Prime Minister Manuel Valls has warned that there will be "new attacks" in France, but said that proposals by former president Nicolas Sarkozy to boost security were not the right way to deal with the threats.
Paris was put on high alert last week after French officials said they dismantled a "terrorist cell" that planned to attack a Paris railway station under the direction of the Islamic State of Iraq and the Levant (ISIL).
French police also arrested a 15-year-old boy suspected of planning a separate attack, investigators said on Sunday.
The teenager was detained in eastern Paris on Saturday after having been under house arrest since April for suspected links to ISIL members.
"This week at least two attacks were foiled," Manuel Valls said in an interview with Europe 1 radio and Itele television on Sunday.
"There will be new attacks, there will be innocent victims ... this is also my role, to tell this truth to the French people," Valls said.
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Valls also warned that the country faced a threat from 15,000 others in the country who were on the radar of police and intelligent services.
In an interview with newspaper Le Journal du Dimanche, Sarkozy proposed to systematically place French citizens suspected of having links to fighters in special detention facilities.
"And don't tell me it would be Guantanamo," Sarkozy said in the interview. "In France, any administrative confinement is subject to subsequent control by a judge."
Guantanamo Bay Detention Camp, opened by former United States President George W Bush, was used to hold prisoners rounded up overseas after the US became embroiled in wars in Afghanistan and Iraq following the September 11, 2001 attacks on New York and Washington.
Interior Minister Bernard Cazeneuve said that French police had arrested 293 people this year for "links to terrorist networks".
Investigators believe an ISIL operative had been in contact with one of the women arrested last week in connection with a car found abandoned a week ago near Notre Dame cathedral, a major tourist draw in central Paris.
The car contained five gas cylinders, three bottles of diesel and a lit cigarette.
Paris prosecutor Francois Molins said the women were acting on orders coming from Syria.
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One woman named as Ornella G was remanded in custody on Saturday on terrorism charges, after her fingerprints were found on the vehicle.
She told police she and an accomplice had tried to set the vehicle alight but fled when they saw a man they believed to be a plain-clothes policeman.
Three other women, alleged members of the same cell, have also been detained. Police sources believe the three were planning another attack.
One of the women has been linked to one of the attackers who killed a French priest in Normandy in July, and to an assailant who stabbed a police couple to death at their home in a Paris suburb in June.
France is on heightened alert after a series of attacks since January 2015 that have killed 238 people and made security a hot topic in campaigning for next year's presidential and parliamentary elections.
ISIL claimed responsibility for the Paris attacks in November which killed 130 people, and also claimed that the truck driver who crushed 86 people to death in Nice in July was one of the group's "soldiers".