Attackers who killed 129 people in a wave of shootings and suicide bombings in Paris appeared to be made up of three teams, Paris Prosecutor Francois Molins says.
Islamic State has claimed responsibility for Friday night's attacks which President Francois Hollande said amounted to an act of war against France.
Officials put the number of injured at 352, with 99 people in a critical condition.
- Arrests of three men in Belgium on Saturday are linked to the attacks.
- Several Kalashnikovs have been found in an abandoned car believed to have been used by some of the attackers, say French judicial sources.
- One attacker was a French man who was known to authorities and he has been named as Ismail Mostefai.
- Islamic State claims responsibility for attacks in official statement.
- President Francois Hollande says the attack amounts to an act of war against France.
- Seven attackers are confirmed killed, and all had been heavily armed and wearing explosive belts.
Read more on the response to the deadly attacks
Paris prosecutor Francois Molins confirmed French authorities had a security file for Islamist radicalisation on one of the dead attackers, a 30-year-old Frenchman who also had a criminal record but had never spent time in jail.
Omar Ismail Mostefai was identified by his severed finger, which was found among the rubble of the Bataclan concert hall.
The 29-year-old was one of three men who blew himself up, killing scores of people in the bloodiest scene of the carnage.
The French national's criminal record shows eight convictions for petty crimes between 2004 and 2010, but no jail time.
Mostefai had "never been implicated in an investigation or a terrorist association".
Investigators were looking into whether he took a trip to Syria last year.
The arrests of three men in Belgium were linked to the attacks and a person who had hired one of the cars used in the attacks was stopped at the Belgian border, said Mr Molins.
Seven attackers had been killed, and all had been heavily armed and wearing explosive belts.
The father and brother of a French gunman linked to the deadly Paris attacks have been taken into custody, AFP reported. Sources close to the investigation said police were searching the father's home in the small town of Romilly-sur-Seine, about 130km east of Paris, as well as his brother's in nearby Bondoufle.
Police leave was cancelled and 1500 army reinforcements were drafted into the Paris region as authorities sought accomplices of the gunmen.
Prosecutors said the slaughter - claimed by Islamic State as revenge for French military action in Syria and Iraq - appeared to involve a multinational team with links to the Middle East, Belgium and possibly Germany as well as home-grown French roots.
Belgian federal prosecutors said police had arrested at least three people in Molenbeek, a poor district of Brussels.
The operation was focused on a car rented in Belgium and found near Paris's Bataclan concert hall where, in the most deadly of the series of attacks, gunmen killed at least 89 people.
The prosecutors declined to comment on whether those arrested were previously known to authorities or whether any of them were in Paris on Friday.
Earlier, Belgian Justice Minister Koen Geens said "multiple searches and arrests" had been made without specifying numbers.
Some 40 more people were killed in five other attacks in the Paris region, including an apparent double suicide bombing outside the Stade de France national stadium, where Mr Hollande and the German foreign minister were watching a friendly soccer match between France and Germany.
At least two of those killed in the attacks were Belgian, and other foreign victims included a US student, a British man, a 29-year-old Spaniard, two nationals of Algeria, one person from Morocco, and two young sisters from Tunisia. New Zealand's Ministry of Foreign Affairs has confirmed no New Zealanders were killed or injured in the attacks.
Second suspect may have entered via Greece
Meanwhile, Greek government sources said a second suspect among the gunmen was likely to have entered Europe through Greece.
Earlier, deputy police minister Nikos Toskas said a Syrian passport was found near the body of one of the gunmen who died in the attacks who had passed through Greece in October.
The passport's owner was a young man who had arrived in Leros on a small vessel from Turkey with a group of 69 refugees and had his fingerprints taken by Greek officials, a police source said.
However, a security expert said it was possible the Syrian passport was planted as part of a plan to excerbate tensions against refugees.
Intelligence analyst Dr Paul Buchanan said the man passed through Greece only in October, which would not give much time to plan an attack of this scale.
Islamic State wanted to deepen and exploit the divide between muslim and non-muslims in Europe, and a hardening of any stance against refugees played into their hands, he said.
The day after the attacks, mourners gathered at a makeshift memorial in Place de la Republique in Paris.
- Reuters / BBC