A women wearing a mask reading "I am Charlie" takes part in a solidarity march (Marche Republicaine) in the streets of Paris January 11, 2015.[Photo/Agencies]

France's Agence Juive, which tracks Jewish emigration, estimates more than 5,000 Jews left France for Israel in 2014, up from 3,300 in 2013, itself a 73 percent increase on 2012.

While there has been widespread solidarity with the victims, there have been dissenting voices. French social media have carried comments from those uneasy with the "Je suis Charlie" slogan interpreted as freedom of expression at all cost. Others suggest there was hypocrisy in world leaders whose countries have repressive media laws attending the march.

Far-right National Front leader Marine Le Pen, whom analysts see receiving a boost in the polls due to the attacks, said her anti-immigrant party had been excluded from the Paris demonstration and would instead take part in regional marches.

In Germany, a rally against racism and xenophobia on Saturday drew tens of thousands of people in the eastern German city of Dresden, which has become the centre of anti-immigration protests organised by a new grassroots movement called PEGIDA.

Separately, a building of the newspaper Hamburger Morgenpost, which like many other publications has reprinted Charlie Hebdo cartoons, was the target of an arson attack and two suspects were arrested, police said on Sunday.

Turkish and French sources said a woman hunted by French police as a suspect in the attacks had left France several days before the killings and is believed to be in Syria.

French police had launched in an intensive search for Hayat Boumeddiene, the 26-year-old partner of one of the attackers, describing her as "armed and dangerous".

But a source familiar with the situation said Boumeddiene left France last week and travelled to Syria via Turkey. A senior Turkish official corroborated that account, saying she passed through Istanbul on Jan. 2.