One Europe1 News journalist said: “Several men in black hoods were heard to shout ‘the Prophet has been avenged’.”
Europe 1 also reported that Martin Boudot, a journalist working for a production company in the same building, who witnessed the attack and sought refuge on the roof said: "I saw two people wearing black hoods who ran outside shouting 'Allah Akbah' and shot at policmen outside."
French President Francois Hollande said the attackers were still on the run.
UK Prime Minister David Cameron tweeted: "The murders in Paris are sickening. We stand with the French people in the fight against terror and defending the freedom of the press."
Israeli Prime Minister Benjamin Netanyahu warned that: "The heinous acts we saw today in Paris won't be the last".
He added: "On behalf of all Israelis,I extend condolences to President Hollande,the bereaved families and to the French people.
"All of Israel stands with you on this difficult day."
The attack was condemned by communal groups.
Moshe Kantor, president of the European Jewish Congress, said: “This is a war against freedom of speech and the European way of life which has already seen Jewish children gunned down at school and people murdered in cold blood while visiting a museum in Brussels.
“We must use all tools necessary to prevent these terrorist attacks which must begin with a significant clampdown on extremists and those that promulgate hate. The authorities must take preventative measures, but also increase the powers of law enforcement agencies and increase intelligence cooperation to ensure that these types of attacks do not happen again.”
Paul Charney, chairman of the Zionist Federation, said extremist “warped ideology has been responsible for the violent increase in antisemitism in the country.
"We must all work together to make sure our shared values of liberty, equality and fraternity are not undermined by this horrific attack.”
The magazine has previously published front page controversial cartoon of a Charedi pushing a Muslim man in the wheelchair – with the latter saying “No mocking”. In reference to a French film, it was titled “Untouchables 2”.
Chief Rabbi Ephraim Mirvis said: “This publication has a long record of iconoclastic and provocative satire. The cover of one controversial issue of Charlie Hebdo in 2012 depicted an ultra-Orthodox Jew pushing a wheelchair-bound Muslim, labelling both as aspiring to immunity from mockery: it satirised both my religion and Islam together. I found this cartoon and other material they have published offensive, but this does not in any way dilute or diminish my outrage and anguish at today’s massacre.
"We repudiate with anger the suggestion that terrorism of the kind we have seen today is done in God’s name, is countenanced by Him, or is in any way sanctified by purported religious motivation.
"We offer our condolences to the grieving families and to the French people as a whole and in particular to the professionals in the worlds of journalism and cultural commentary who will rightly interpret this violence as an attack on their freedom of expression.”
