Journalists have led thousands tweeting the hashtag "Je Suis Charlie" in messages of solidarity with victims of the attack at the Paris office of French satirical weekly Charlie Hebdo.
"Je Suis Charlie" translates as "I am Charlie".
Twelve people were killed when gunmen attacked the building before fleeing in a black Citroën hatchback. They then shot dead two police officers.
Four of France’s best-known satirical cartoonists, including the magazine's editor, are among those killed in the attack. Ten journalists died in total and twelve others were injured, some seriously.
#JeSuisCharlie Journalism is printing what someone else does not want printed: everything else is public relations. ~ George Orwell— AndreaSyrtash (@AndreaSyrtash) January 7, 2015
The magazine’s editor and chief cartoonist, Stéphane Charbonnier, known as "Charb" had previously defended a controversial series of cartoons published in the magazine depicting the Prophet Mohammed in 2012.
Now isn't the time for populism or Islamophobia. Now is the time to stand up for free speech, everywhere, on anything. #JeSuisCharlie— Adam Seldon (@adamJseldon) January 7, 2015
#JeSuisCharlie Remember, every statement one makes offends someone. Still, humor, satire, news & individuals' voices must all remain free.— Laura Wells (@wellsla) January 7, 2015
I'm a Muslim journalist. Although I disagree w/ anti-Islam cartoons, my faith compels me to respect the rights of others. #JeSuisCharlie— Sarah Harvard (@sarah_harvard) January 7, 2015
You can kill journalists, cartoonists. You can't kill the freedom of the press. You have only made their message stronger. #JeSuisCharlie— Emily Koch (@EmilyKoch22) January 7, 2015