Twelve people have been shot dead at the headquarters of the French satirical magazine Charlie Hebdo in Paris, say police.
Two masked gunmen are reported to have stormed the offices of the controversial publication, which has previously been attacked over its portrayal of the Prophet Mohammed.
They are believed to have been armed with Kalashnikov rifles and a rocket-propelled grenade.
According to the AFP news agency, the attackers shouted: “We have avenged the prophet.”
A manhunt is under way for the gunmen, who escaped after a shootout in the street with police.
A dramatic photograph has been published in Le Monde newspaper of two gunmen dressed in black, standing either side of vehicle, apparently pointing their weapons at a police car.
And graphic footage taken from the top of a building shows a firefight in the street below, shouting and gunfire can be heard and two people can be seen levelling weapons.
There is also film of a police officer being executed by the gunmen as he lies on the ground, holding his hands up.
The dead are believed to include two police officers. Four people have also been critically injured.
Ambulances are at the scene.