tweets:, external As a Muslim, I condemn the cruel attack on #CharlieHebdo & offer condolences to the French people. The "Islam" of the murderers is not mine.

US President Barack Obama has condemned the Paris attack and what he calls "the hateful vision of these killers".

@siobhanheanue tweets:, external Parisians will take to the streets tonight, for freedom of the press, democracy and the Republic #CharlieHebdo

Reuters is reporting that Jyllands-Posten, the Danish newspaper that triggered protests in some Muslim countries after publishing cartoons of the Prophet Muhammad, has increased its security following today's attack.

French Interior Minister Bernard Cazeneuve is currently giving a statement. He says that the authorities are hunting three attackers in connection with the shooting.

Anne Hidalgo, the mayor of Paris, has released a statement, external on Facebook condemning the attack and calling for a march on Thursday through Paris's Republic Square at 6pm.

She says: "I feel a sense of absolute horror at the attack... We must respond to this act through the sacred union around the principles of the Republic."

Image source, facebook

People are using the hashtag "#JeSuisCharlie, external" (I am Charlie) to express sympathy for the people killed in the attack in Paris.

Image source, Twitter

Jacques Myard, French MP with opposition party UMP, said: "We knew something would happen. The (security) services used to say to us it's not if but when and where. We know that we are at war. The Western nations - like Britain, France, Germany - we are at war."

tweets:, external "Still no attacks in France. We have until end of Jan to present wishes."Chilling prophecy by @Charlie_Hebdo_, external's Charb:

Image source, Twitter

French Justice Minister Christiane Taubira reacts outside the headquarters of Charlie Hebdo.

Image source, AFP

Stephane Charbonnier, the magazine's editor-in-chief reportedly killed in the attack, had received death threats in the past and was living under police protection.

More from the US: White House spokesman Josh Earnest told CNN he condemned the attack in the strongest possible terms. "It's not just an attack on the people of France, it's an attack on some of the basic values we hold dear in this country - freedom of speech, freedom of expression and a free press."

@rayverma tweets:, external #Paris, you're on my mind. The darkest moment in the history of French media. To my French family - stay safe. #ParisShooting #CharlieHebdo

@MadJoannaOlive tweets, external: "This is not in the name of Islam. These ppl don't represent ANY religion. No matter what they say. Disgraceful & heartbreaking #CharlieHebdo, external"

The French government has sent soldiers to protect public spaces in Paris.

Image source, AFP

Three other cartoonists killed have been named by AFP as Jean Cabut ("Cabut"), Bernard Verlhac ("Tignous") and Georges Wolinski ("Wolinski").

The director of Le Monde newspaper, Gilles Van Kote, has condemned, external the attack on Charlie Hebdo, saying: "The killing that occurred [today] only reinforces our belief that it is necessary to fight against ignorance, intolerance, obscurantism and fanaticism. It is more vital than ever to remember that freedom of the press is not negotiable."

Danish cartoonist Kurt Westergaard, whose work depicting the Prophet Muhammad was reprinted in Charlie Hebdo, said he hoped "the moderate majority of Muslims" would condemn the attack.

BBC Trending has pulled together some of the tweets to emerge from the attack.

The editor-in-chief of Charlie Hebdo, Stephane Charbonnier, known as Charb, has reportedly been killed in the attack, judicial sources tell Agence France Presse.