At least 12 people have been killed in a shooting incident at the Paris office of French satirical weekly Charlie Hebdo, police have said.
Witnesses and police officials said multiple gunmen were involved, and that they were seen armed with AK47s and pump action shotguns. According to France's AFP news agency, the men were armed with at least one rocket launcher.
A police spokesperson confirmed that the death toll had risen to 12, and that up to 10 others were injured. Five were reported to be in critical condition.
Officials said two police officers were among those killed, and that the other 10 were journalists. Luc Poignard, an official with the French police union official, had earlier confirmed that three officers had been injured and that the attackers had escaped in two vehicles.
Paris has raised its terror alert to the highest setting in the aftermath of the attack, while the gunmen themselves are still reported to be on the run.
Video footage posted to social media showed armed gunmen running through the streets of Paris, shooting with automatic weapons and shouting "Allahu Akbar."
French President Francois Hollande has traveled to the scene in Paris's 11th arrondissement after what he called the "terrorist attack of the most extreme barbarity."
Armed gunmen face police officers near the offices of the French satirical newspaper Charlie Hebdo in Paris.
A victim is evacuated on a stretcher.
He said it was the latest in a series of terrorist incidents on French soil, and that the nation was in a state of shock. "We are a country of liberty, and because of that we receive threats," he said.
A number of French media outlets reported that the dead included the magazine’s editor and chief cartoonist, StÃ©phane Charbonnier, known as "Charb," and Jean Cabut or "Cabu," a veteran of several French newspapers and reportedly the highest paid cartoonist in the world.
French President Francois Hollande (C) arrives after a shooting at the Paris offices of Charlie Hebdo.
Firefighters and police officers gather in front of the offices.
A year earlier, its offices had been firebombed after a spoof issue featured a caricature of Mohammed on its cover. According to Le Monde, a source said that one of the magazine's cartoonists, known as Riss, was injured during the attack.
A bullet's impact on the window of the offices.
Firefighters carry an injured man on a stretcher.
Gilles Boulanger, who works in the same building as the Charlie Hebdo offices, likened the scene to a war zone.
He told the BBC: "A neighbour called to warn me that there were armed men in the building and that we had to shut all the doors. And several minutes later there were several shots heard in the building from automatic weapons firing in all directions. "So then we looked out of the window and saw the shooting was on Boulevard Richard-Lenoir, with the police. It was really upsetting. You'd think it was a war zone."
Another witness, Benoit Bringer, told TV station France Info: "We heard shouting in the street. We saw hooded men carrying Kalashnikovs enter the building. We called the police. After a few minutes we heard heavy firing, a lot of firing. We went upstairs onto the roof. After about 10 minutes we saw two armed men come out into the street. Three policemen arrived on bikes but had to leave because the men were armed. There was a lot more shouting in the street, a lot more gunshots. The attackers took off in a car."
David Cameron led the British response to the unfolding incident, condemning the attack on Twitter.
"The murders in Paris are sickening," he said. "We stand with the French people in the fight against terror and defending the freedom of the press."
Philip Hammond, the British Foreign Secretary, wrote: "Appalled to hear news of apparent terrorist attack in Paris. My thoughts are with the family and friends of those killed."
A Twitter campaign under the banner #JeSuisCharlie has quickly grown momentum as thousands pledge support for the magazine and to the victims of the attack.