French Police are hunting two masked gunmen who shot dead eleven people at the Headquarters of the French satirical magazine, Hebdo, in Paris.
The controversial publication had previously been attacked over its portrayal of the Prophet Mohammed.
Eye witnesses report that they were armed with Kalashnikov rifles and a rocket-propelled grenade.
The dead are believed to include two police officers. Four people have also been critically injured.
According to Sky News reports, three officers had initially arrived on pushbikes, but left when they realised how heavily-armed the raiders were.
The gunmen are believed to have left several minutes later and attempted to car-jack a vehicle.
Benoit Bringer, a journalist with Agence Premiere Ligne who saw the attack, told the iTele network he saw several masked men armed with machine guns.
Henry Samuel, the Daily Telegraph’s Paris correspondent, told Sky News: “According to people on the ground, two masked gunmen burst into the offices very heavily armed, (with) Kalashnikovs, apparently even with a rocket-propelled grenade, and opened fire, leaving several minutes later.
“Somebody who was nearby on the roof and saw much of the incident said three policemen then arrived on a pushbike. When they saw how armed these men were they left and then there was a kind of gunfight in the street.”
French President Francois Hollande is now at the scene amid heavy security.
He said the security level in Paris had been raised, and the gunmen were being hunted.
“We have to be firm, we have to be strong,” he said.
“We will punish the attackers.”
He added: “France is in shock. We are a united country.”