A man holds a sign reading "I Am Charlie" as people gather on Union Square January 7, 2015 in New York
Washington (AFP) - Hundreds in Washington, New York and Canada rallied Wednesday night in the frigid cold proclaiming "I am Charlie" in solidarity with those killed in a deadly attack on French magazine Charlie Hebdo.
Some 200 to 300 French and American protesters gathered in the nation's capital in front of the Newseum, a museum dedicated to news, waving signs and French flags emblazoned with the now ubiquitous rallying cry "Je suis Charlie."
Among them International Monetary Fund Managing Director Christine Lagarde, of France, said she attended the rally to show solidarity as well as sympathy for the victims.
"We are all still in shock," Lagarde said, recalling the "cartoonists who who have been a part of our daily lives for years."
Masked, black-clad gunmen killed 12 people at the satirical weekly in a chilling confrontation when they stormed into its Paris offices in broad daylight and shouted "Allahu akbar."
- 'We're all Charlie' -
Against a wind chill of minus four degrees Fahrenheit (minus 20 Celsius), several hundred mostly French protesters gathered in New York's Union Square to denounce the attack, singing the La Marseillaise and chanting "Charlie, Charlie."
"I'm a journalist. I'm of the Charlie generation, we're all Charlie," said an overwhelmed Mylene Mass, 28. "It's horrible. But they didn't succeed. They made all of France take a stand together."
Vigils were held in bone-chilling weather across Canada as well, with more than 1,000 people rallying in Montreal and Public Safety Minister Steven Blaney placing a dozen white roses in the snow outside France's consulate in Quebec City.
In Ottawa and Quebec City, where temperatures plunged to minus 40 Fahrenheit (Celsius) in the evening, hundreds more held vigils outside French missions.
And in Hollywood celebrities expressed outrage and support online, with the Motion Picture Association of America making a direct link between the massacre and freedom-of-speech controversy surrounding Sony Pictures, which was hacked and threatened over "The Interview," a comedy about North Korea.
The staff of Charlie Hebdo, which has long provoked controversy, mocking many religions with provocative drawings, was in an editorial meeting when the gunmen arrived.
Among the 12 victims, they picked off eight journalists, including some of France's best-known cartoonists.
"I've been drawn by Cabu, which made me smile at the time," Lagarde said Wednesday, referring to one of the murdered cartoonists, Jean Cabut, who had been known across France by the moniker.
In addition to the dead, prosecutors said 11 people were injured, with four in critical condition.
- 'Thing I'm fanatical about' -
Cartoonists across Latin America including Argentina, Brazil, Chile, Colombia and Ecuador, condemned the episode and created drawings to commemorate the grim attack.
Argentine cartoonist Liniers turned to Twitter, posting a picture in which one person explains to another: "The thing I'm fanatical about is not being a fanatic."
Meanwhile some 100 people including French citizens and Colombian writer Juan Gabriel Vasquez attended a protest in front of a French high school in Bogota.
The Paris attack triggered impromptu demonstrations in cities across the world, including Moscow, London and Tokyo. More than 100,000 gathered across France.
Charlie Hebdo gained notoriety in February 2006 when it reprinted cartoons of the Prophet Mohammed that had originally appeared in Danish daily Jyllands-Posten, causing fury across the Muslim world.
French security forces have launched a massive manhunt for two brothers suspected of the killings, while an 18-year-old suspected accomplice was taken into custody after surrendering.