As many as six members of a 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 slain gunmen, French officials said Monday.
Two French police officials, who spoke on condition of anonymity, said that authorities were searching the Paris area for the Mini Cooper registered to Hayat Boumeddiene, the widow of Amedy Coulibaly, who assaulted a kosher grocery on Friday and killed four hostages.
Boumeddiene is now in Syria, according to Turkish officials.
France deployed 10,000 troops to protect sensitive sites in the wake of the attacks that killed 17 people last week. Brothers Cherif and Saïd Kouachi, as well as Coulibaly, their friend who claimed ties to extremists in the Middle East, also died Friday in clashes with police.
Prime Minister Manuel Valls said the manhunt is urgent because "the threat is still present" after the attacks that began Wednesday with 12 people killed at the satirical weekly Charlie Hebdo.
Paris' Marais district — one of the country's oldest Jewish neighborhoods — was filled with police and soldiers by midday Monday. About 4,700 of the security forces would be assigned to protect France's 717 Jewish schools, Interior Minister Bernard Cazeneuve said.
"A little girl was telling me earlier that she wanted to live in peace and learn in peace in her school," said Cazeneuve after a visit to a Paris Jewish classroom, where the walls were covered with children's drawings of smiling faces. "That's what the government, that's what the Republic, owes to all the children in France: security in all schools, especially in the schools that could be threatened."
Defense Minister Jean-Yves Le Drian said the nationwide deployment of troops would be completed by Tuesday and would focus on the most sensitive locations.
"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.
Video emerged Sunday of Coulibaly explaining how the attacks in Paris would unfold. French police want to find the person or people who shot and posted the video, which was edited after Friday's attacks.
Boumeddiene was seen traveling 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.
Security camera video footage shown Monday by Turkey's Haberturk newspaper showed Boumeddiene arriving at Istanbul's Sabiha Gokcen airport on Jan. 2. A high ranking Turkish official, who spoke on condition of anonymity, confirmed that 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. She and her traveling companion, a 23-year-old man, toured Istanbul, then left Jan. 4 for a town near the Turkish border, according to a Turkish intelligence official.
Her last phone signal was on Jan. 8 from the border town of Akcakale, where she crossed, apparently into territory controlled in Syria by the Islamic State of Iraq and the Levant, or ISIL. Their Jan. 9 return plane tickets to Madrid went unused.
Al Jazeera and news services