Friday’s attacks by Islamist militants in Paris were planned and organised from Syria, French Prime Minister Manuel Valls has said.
He added that the authorities believed new terror attacks were being planned in France and other European countries.
Meanwhile, two more attackers have been named, as well as the five already identified.
A total of 129 people died in the attacks on bars and restaurants, a concert hall and the Stade de France.
France is to hold a nationwide minute of silence at midday local time (11:00 GMT) for the victims.
A huge manhunt is under way for surviving members and accomplices of the Islamist group that carried out the attack.
Police have named Brussels-born Salah Abdeslam, 26, as a key suspect. He was reportedly stopped by officers in the wake of the attacks – but then let go.
Meanwhile, French aircraft have attacked Raqqa, the stronghold in Syria of the Islamic State group, which has said it carried out the attacks.
Mr Valls said that France was dealing with a “terrorist army”, rather than a single terrorist group.
“We know that operations were being prepared and are still being prepared, not only against France but other European countries too,” he said, quoted by AFP news agency.
Suspected Paris attackers
- Salah Abdeslam, 26 – urgently sought by police
- Mohammed Abdeslam – reportedly arrested in Belgium
- Brahim Abdeslam, 31 – named as attacker who died near Bataclan concert hall
- Omar Ismail Mostefai, 29, from near Paris – died in attack on Bataclan
- Bilal Hadfi, 20 – named as attacker who died at Stade de France
- Ahmad al-Mohammad, 25, from Idlib, Syria – died at Stade de France (unverified)
- Samy Amimour, 28, from near Paris – suicide bomber at Bataclan
- Two other attackers died during the assaults in the city
The prime minister said more than 150 raids on militant targets had been carried out in different areas of France early on Monday.
“We are making use of the legal framework of the state of emergency to question people who are part of the radical jihadist movement… and all those who advocate hate of the republic,” he said.
Police sources told news agencies that properties in the Paris suburb of Bobigny, as well as the cities of Grenoble, Toulouse and Lyon, had been targeted.
Reports said large amounts of weapons were found and several people arrested.
A building in the Brussels district of Molenbeek was also raided, Belgian media reported.
Seven attackers died in the assault on the French capital, most of them after detonating suicide belts.
Five were identified over the weekend, and on Monday another two were named by the Paris prosecutor as Ahmad al-Mohammad and Samy Amimour.
Al-Mohammad is the name on a Syrian passport found with the remains of one of the attackers, though the man’s identity has not yet been verified. The other attackers so far named are all from Europe.
Amimour was said to be facing terrorism charges in France.
He was placed under judicial supervision while under investigation for terrorist conspiracy – he planned to go to Yemen.
An international arrest warrant was issued against him when he broke bail in autumn 2013.
Three of his relatives were among those detained this morning.
Salah Abdeslam, the man named by police as a key suspect, is said to have rented a VW Polo car that was found near the Bataclan concert hall, where 89 people died, and believed to have been used by attackers.
On Saturday he was in a vehicle with two other men near the Belgian border when it was stopped by police, officials said, but was released after checks.
Belgian police again stopped the car in Molenbeek but he was no longer inside, France’s Le Monde newspaper reported.
It is unclear whether the French authorities had matched the VW Polo found at the Bataclan venue to him at the time he was stopped.
Police have described Salah Abdeslam as dangerous, and warned people not to approach him.
One of the main lines of investigation concerns Molenbeek, which has a reputation as being a haven for jihadists. One of Abdeslam’s brothers, Mohammed, was reportedly arrested there when he returned from Paris.
He remains in custody. Belgian police say they have made a total of seven arrests.
Belgium’s Premier Charles Michel said the Belgian authorities would crack down on Molenbeek.
France is currently marking a second day of national mourning. A state of emergency declared by President Hollande remains in force. Thousands of extra police and troops are on the streets of Paris.
Main attack sites:
Bataclan concert venue, 50 Boulevard Voltaire, 11th district – 89 dead when stormed by gunmen, three of whom were killed; another gunman died nearby
La Belle Equipe, 92 rue de Charonne, 11th district – 19 dead in gun attacks
La Casa Nostra restaurant, 92 rue de la Fontaine au Roi, 11th district – five dead in gun attacks
Stade de France, St Denis, just north of Paris – explosions heard outside venue, three attackers and a bystander killed
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