As many as six members of a terrorist cell involved in the Paris attacks may still be at large, including a man who was seen driving a car registered to the widow of one of the gunmen, French police said Monday.

The disclosure came as France deployed 10,000 troops to protect sensitive sites — including Jewish schools and neighbourhoods — in the wake of the attacks that killed 17 people last week.

Brothers Cherif and Said Kouachi and their friend, Amedy Coulibaly, were killed Friday by police after a murderous spree at the satirical newspaper Charlie Hebdo and a kosher supermarket. The three all claimed ties to Islamic extremist groups.

Two police officials told The Associated Press that authorities were searching the Paris area for the Mini Cooper registered to Hayat Boumeddiene, Coulibaly's widow. Turkish officials say she is now in Syria.

One of the police officials said the cell consisted of about 10 members, and that "five or six could still be at large," but he did not provide their names. The other official said the cell was made up of about eight people and included Boumeddiene.

France Attacks

Soldiers stand guard outside a synagogue in Paris, Monday, Jan. 12, 2015. All of France's 717 Jewish schools will be given extra security in the wake of the attacks. (Jacques Brinon/Associated Press)

One of the other men believed to be part of the cell has been seen driving Boumeddiene's car around Paris in recent days, the two officials said, speaking on condition of anonymity because they were not authorized to discuss the investigation with the media. They cautioned that it was not clear whether the driver was an operative, involved in logistics, or had some other, less-violent role in the cell.

An Interior Ministry official declined to comment on an ongoing investigation, and a spokeswoman for the Paris prosecutor's office was not immediately available for comment.

'The threat is still present'

One of the police officials also said Coulibaly apparently set off a car bomb Thursday in the town of Villejuif, but no one was injured and it did not receive significant media attention at the time.

Prime Minister Manuel Valls said the manhunt is urgent because "the threat is still present" from the attacks.

"The work on these attacks, on these terrorist and barbaric acts continues ... because we consider that there are most probably some possible accomplices," Valls told BFM television.

The nationwide deployment of troops would be completed by Tuesday and would focus on the most sensitive locations, Defense Minister Jean-Yves Le Drian said.

By midday Monday, soldiers and police filled Paris' Marais district — one of the country's oldest Jewish neighbourhoods. About 4,700 of the security forces would be assigned to protect France's 717 Jewish schools, Interior Minister Bernard Cazeneuve said.

Late Monday, the website of the newspaper Liberation, which has been hosting the Charlie Hebdo staff, posted an image of the next cover of the satirical weekly. It featured a cartoon of a bearded man in a turban with a tear streaming down his cheek, and holding a sign: "Je Suis Charlie" — "I Am Charlie."

Overhead was the phrase: "All is forgiven."

4th suspect believed to be in Syria

The attacks began Wednesday with 12 people killed at the publication Charlie Hebdo, which had lampooned Islam and other religions, by gunmen the police identified as the Kouachi brothers. Police have said, however, that the attack was carried out by three people.

Authorities said Coulibaly killed a policewoman Thursday and then killed four people at the kosher market Friday before he was slain by police.

Video emerged Sunday of Coulibaly explaining how the attacks in Paris would unfold. French police want to find the person or persons who shot and posted the video, which was edited after Friday's attacks.

France Market Attack

Hayet Boumddiene, suspect in the kosher market attack, crossed the border into Syria on Jan. 8, according to a Turkish official. (Prefecture de Police de Paris/Associated Press)

Boumeddiene was seen travelling through Turkey with a male companion before reportedly arriving in Syria with him on Jan. 8 — the day after the Charlie Hebdo attack and the same day Coulibaly began his murderous spree by killing the policewoman.

According to security camera video shown Monday by Turkey's Haberturk newspaper, Boumeddiene arrived Jan. 2 at Istanbul's Sabiha Gokcen airport. A high-ranking Turkish official, who spoke on condition of anonymity, confirmed the woman on the video was Boumeddiene.

Turkish intelligence then tracked Boumeddiene from her arrival.

Turkish Foreign Minister Mevlut Cavusoglu told the state-run Anadolu Agency that she had stayed at a hotel in Istanbul with another person before crossing into Syria on Thursday.

Hayat Boumeddiene Istanbul

Turkish officials said Boumeddiene had arrived in Istanbul from Madrid on Jan. 2. It is believed she made her way to Syria. (CCTV/Reuters)

She and her travelling companion, a 23-year-old man identified as Mehdy Sabry Belhoucine, toured Istanbul before leaving Jan. 4 for a town near the Turkish border, according to a Turkish intelligence official who was not authorized to speak by name. Little was known about Belhoucine.

Her last phone signal was Jan. 8 from the border town of Akcakale, where she apparently crossed into Islamic State-controlled territory in Syria, the official said. Their Jan. 9 return plane tickets to Madrid went unused.

Police release raid videos

French police have released videos of their operations around two sieges on Friday after the attacks by the Islamic militants.

The videos were issued by the Interior Ministry on Sunday in what French media said was an unusual move.

The videos show the prelude to the raid in Dammartin en Goele and footage of hostages released from the second siege at the kosher supermarket in Paris.

On mobile? Watch the video here

In the Paris footage, police from the Groupe d'Intervention de la Gendarmerie Nationale (GIGN) are seen hurrying hostages from the supermarket after the police blew up the shop entrance and stormed in to tackle Coulibaly, who had killed four hostages.

Islamophobic rallies in Germany

In Dresden, Germany, thousands of people attended a weekly anti-Islam rally — its biggest turnout yet — after organizers declared it a tribute to the victims of the Paris attacks.

Organizers said 40,000 people participated, while Dresden police put the figure at over 25,000 people — still considerably more than the 18,000 who came last week.

The group, which calls itself Patriotic Europeans against the Islamization of the West, or PEGIDA, had asked supporters to wear black ribbons as a show of respect for those killed last week.

"The terrible acts of Paris are further proof that PEGIDA is needed," said Lutz Bachmann, one of the organizers of the Dresden rally.

Germany anti-Islam anti-immigration protests

A record 25,000 anti-immigration protesters marched through the east German city of Dresden on Monday. (Fabrizio Bensch/Reuters)

With files from Reuters