PARIS (AFP) - A bloodbath in the editorial conference, police gunned down execution-style in the street, a desperate manhunt - a timeline of France's worst attack in at least 40 years:

At around 11.20am (6.20pm Singapore time), two masked Kalashnikov-wielding men dressed in black burst into No. 6 rue Nicolas-Appert in a Paris neighbourhood, where the archives of the Charlie Hebdo satirical weekly are based.

"Is this Charlie Hebdo?" they screamed, before realising they had got the wrong address.

Moving quickly down the road to No. 10, they fired at reception staff and moved to the second floor where journalists and cartoonists were in the middle of an editorial conference.

"The two men opened fire and coldly killed the people in the conference room, as well as the police officer in charge of protecting (cartoonist) Charb, who did not have time to react," said a police source.

Only one person survived, by hiding under the table. The witness heard the pair cry "we have avenged the prophet" and "Allahu akbar" (God is greatest).

POLICE ARRIVE

At 11.30am, police received reports of gunshots at the Charlie Hebdo headquarters and immediately dispatched officers to the scene.

The gunmen fled, again crying "Allahu akbar", and came face-to-face with police, with a firefight ensuing.

They climbed into a black Citroen C3 car and exchanged fire with another police vehicle, shooting it around a dozen times without injuring the officers inside.

According to chilling amateur video footage, the killers went about their deadly work with blood-curdling calm - striding with guns held before them and scanning the streets for targets, before unflinchingly executing an injured police officer sprawled on the pavement as he held his hand aloft in an apparent attempt to shield himself.

The two killers then cast another look around and slowly jogged back towards their waiting getaway car, where the figure on the passenger side paused to scoop up what appeared to be a gun that had fallen to the ground before jumping in.

Once aboard, the two assassins drove off with the same calm as they had methodically carried out their strike.

Other people in the area with the presence of mind and courage to record videos or take photos of the violence captured a pedestrian crouching between parked cars after apparently spotting the killers advancing up the street.

Shortly after, the gunmen had a violent crash with a Volkswagen, injuring the driver.

They tried to continue but were forced to abandon their damaged vehicle at Porte de Pantin, hijacking another car and fleeing towards the north of the capital.

Police say they have mobilised a huge number of officers to follow the trail of the gunmen but that details of the investigation are currently confidential.