PARIS - For three days, the al-Qaida-linked brothers and a gunman believed to be their partner terrorized France and shook the world.

The Kouachi brothers allegedly carried out the massacre of 12 people at satirical newspaper Charlie Hebdo, while their associate is suspected of killing a policewoman and wounding a street sweeper. On Friday, they hunkered down with hostages in separate sieges that ended in a blaze of gunfire and explosions. A chronology of the terror:

WEDNESDAY, Jan 7:

- Masked gunmen shouting "Allahu akbar!" storm the Paris offices of Charlie Hebdo at noon during an editorial meeting. They head straight for the paper's editor, Stephane Charbonnier, killing him and his police bodyguard. With military-style precision, they go on to slaughter seven other journalists, a maintenance worker and a visitor.

- Making their escape in a black car, the gunmen pause to kill a Muslim police officer, shooting him in the head as he writhes on the ground.

- France raises its terror alert system to the maximum - Attack Alert - and bolsters security with thousands of extra soldiers and officers to guard media offices, places of worship, transport and other sensitive areas.

- World leaders, journalists' groups and others around the world express horror. "This is an act of exceptional barbarism," says French President Francois Hollande.

- French police identify three suspects: The two brothers Cherif Kouachi, 32, and Said Kouachi, 34, and a suspected accomplice, 18-year-old Mourad Hamyd. A witness quotes the gunmen as saying: "You can tell the media that it's al-Qaida in Yemen."

- Thousands of demonstrators jam the Place de la Republique - Republic Square - near the site of the shooting to honor the victims. They wave pens and papers reading "Je suis Charlie" - "I am Charlie" - a slogan of solidarity that went viral on Twitter. Similar rallies are held in London's Trafalgar Square as well as Madrid, Barcelona and Berlin.

- Hamyd turns himself in at a police station in Charleville-Mezieres, a town in France's eastern Champagne region.

- Heavily armed police move into the city of Reims, also in Champagne, apparently searching for the Kouachi brothers.