Paris shooting: Editor, cartoonists among the dead
The magazine has been repeatedly threatened for its caricatures of Prophet Mohammad.
JOHANNESBURG - _Charlie Hebdo _Editor-in-Chief Stephane Charbonnier and four well-known cartoonists are among the 12 people killed in an apparent terror attack in Paris.
Several videos showed three masked gunmen shouting "We have avenged the prophet" shortly before opening fire.
The suspects entered the building of the satirical magazine on Wednesday, armed with a rocket launcher and rifles, critically wounding five people.
Two police officers are among the dead.
It has emerged the Islamic State group had threatened to attack France and minutes before the shooting, Charlie Hebdo tweeted a satirical cartoon of the extremist group's leader sending wishes for the New Year.
The cartoon, titled "Still no attacks in France", had a caricature of an extremist fighter saying "Just wait - we have until the end of January to present our New Year wishes."
The magazine has been repeatedly threatened for its caricatures of Prophet Mohammad and other controversial sketches.
French President Francois Hollande, who visited the scene, said the attack was terror-related.
His cabinet will hold an emergency meeting soon.
A firebomb attack gutted the headquarters of Charlie Hebdo in November 2011 after it put an image of Prophet Mohammad on its cover.
The White House and Britain strongly condemned the shooting and pledged support for France.
German Chancellor Angela Merkel says the shooting is not only an attack on French citizens but also on the freedoms of press and speech.
France raised its terror alert in the greater Paris area to the highest level.
Britain described the attack as "sickening".
It also reaffirmed that it stands beside France in the fight against terror.
The attack, as yet unclaimed, comes amid what a number of commentators identified as rising xenophobia in Europe, with thousands of protesters in several German cities rallying earlier this week against Muslim immigration.
France's five million-strong Muslim population is Europe's largest.
Video: [WARNING: GRAPHIC CONTENT] Paris shooting caught on camera.
Dozens of police and emergency services were at the site as police secured a wide perimeter around the shooting site, where a Reuters reporter saw a car riddled with bullet holes.
Late last year, a man shouting "Allahu Akbar" ("God is greatest") injured 13 by ramming a vehicle into a crowd in the eastern city of Dijon. French officials say several attacks were prevented in recent weeks and Valls has said France had "never before faced such a high threat linked to terrorism".
The last major attack in Paris was in the mid-1990s when the Algerian Armed Islamic Group (GIA) carried out a spate of attacks, including the bombing of a commuter train in 1995 which killed eight people and injured 150.
Additional reporting from Reuters.