French and Belgian police have carried out more than 150 raids in both countries and arrested at least nine people in connection with the deadly Paris attacks .
Monday's early-morning raids by French police took place in Toulouse, Paris, Jeumont and Grenoble, among other locations where officers blocked streets and searched houses looking for suspects involved in Friday's attacks, which killed at least 129 people and wounded hundreds more.
The Paris prosecutor, meanwhile, has identified two more suicide bombers that carried out the attacks in the French capital on Friday.
Ahmad al-Mohammad was named as the attacker who blew himself up at the Stade de France, while Paris-born Samy Amimour was identified as one of the suicide bombers at the Bataclan theatre, where at least 80 people were killed.
Earlier, reports emerged that a fugitive directly involved in the attacks was questioned and let go by police near the Belgian border.
French police had released a photo of Salah Abdeslam, a 26-year-old born in Brussels, who is on the run.
Abdeslam was reportedly stopped and questioned by police at the French-Belgian border before he was allowed through.
He was suspected of renting the car that delivered attackers to the Bataclan concert hall. Abdeslam is one of three brothers believed to be involved in the killings; one was arrested in Belgium and another died in the attack, one official said.
Abdeslam is also under an international arrest warrant issued by Belgium.
France's local media reported 13 raids in Lyon where police said a rocket launcher, among other ammunition, was seized and arrests made.
Al Jazeera's David Chater, reporting from Paris on Monday, said about 200 members of police tactical units surrounded an address in Toulouse and ammunition and a large amount of cash were also found at one of the locations.
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He said 20 police vans were used in the raid in Jeumont on the French-Belgian border where a house was searched.
Late on Monday morning, Belgian police carried out a raid in the Brussels district of Molenbeek, state broadcaster RTBF reported.
Al Jazeera's Paul Brennan, reporting from the Molenbeek district of Brussels where the raid occurred, said the armed police officers had arrived with dogs and had set up a cordon.
The country has also been put on a Level-3 alert, which is the highest it can get, he said.
For his part, Manuel Valls, the French prime minister, confirmed that the raids were linked to Friday's events and gave warning that more attacks were being planned.
"We know that operations were being prepared and are still being prepared, not only against France but other European countries too," Valls told RTL radio.
He said France was "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".
French police had earlier identified Omar Ismail Mostefai, a 29-year-old Paris native, as one of the attackers.
Mostefai's detached finger was found overnight at the Bataclan concert hall, the scene of the bloodiest attack.
The French citizen had been known to police for his alleged links to armed groups but had not been previously linked to violent activities.
Police are also holding six of the man's relatives.
Earlier, French warplanes hit the Islamic State of Iraq and the Levant (ISIL) group's Syrian stronghold of Raqqa as world leaders pledged to renew their fight against the armed group.
In its first air strikes against ISIL since the Paris attacks, 12 warplanes, including 10 fighter bombers, dropped 20 bombs on the targets on Sunday night, the French defence ministry said.
"The first target destroyed was used by Daesh [ISIL] as a command post, jihadist recruitment centre and arms and munitions depot. The second held a terrorist training camp," a ministry statement said.
The planes left from Jordan and the UAE and the strikes were conducted in coordination with US forces, the ministry added.
Source: Al Jazeera and agencies