Key members of the French government will meet Saturday morning to decide on new measures aimed at thwarting a repeat of the attacks in Paris that culminated in a massacre of 12 people at a satirical newspaper, and a supermarket bloodbath that left four hostages dead.
World leaders have telephoned President Francois Hollande to express their personal sympathies. On Sunday Germany's Angela Merkel, Britain's David Cameron as well as Italy's Matteo Renzi, and Spain's Mariano Rajoy have agreed to join in a unity rally in central Paris.
With explosions and gunfire, security forces on Friday ended the three days of terror , killing the two al Qaeda-linked brothers who staged a murderous rampage at the Charlie Hebdo newspaper and an accomplice who seized hostages at a kosher supermarket to try to help the brothers escape.
Twenty people are dead, including the three gunmen. A fourth suspect, Hayat Boumeddiene - the common law wife of the market attacker - is still at large and believed to be armed.
Al Qaeda's branch in Yemen said it directed the attack against the publication Charlie Hebdo to avenge the honor of the Prophet Mohammed, a frequent target of the weekly's satire.
The brothers were not unknown to authorities: One had a terrorism-related conviction for ties to a network sending fighters to battle American forces in Iraq, and both were on the US no-fly list, according to a US official.
Hollande urged his nation to remain united and vigilant, and the city shut down a central Jewish neighborhood following fears of more violence.
"The threats facing France are not finished," Hollande said. "We are a free people who don't cave to pressure."
The drama, which played out on live TV and social media, began with the brothers Said and Cherif Kouachi methodically massacring 12 people Wednesday at the Charlie Hebdo offices.
On Thursday, a gunman that police identified as Amedy Coulibaly shot a policewoman to death south of Paris and, on Friday he attacked the Paris supermarket killing four hostages and threatening more violence unless the police let the Kouachis go.
The attackers had ties both to each other and to terrorist activities that reached back years and extended from Paris to al Qaeda in Yemen. They epitomized Western authorities' greatest fear: Islamic radicals who trained abroad and came home to stage attacks.
It all ended at dusk Friday with near-simultaneous raids in two locations: a printing plant in the town of Dammartin-en-Goele, northeast of Paris, where the Kouachis were holed up, and the kosher supermarket in eastern Paris.
As scores of black-clad security forces surrounded both sites, booming explosions, heavy gunfire and dense smoke heralded the news that the twin sieges finally had ended.
The three gunmen were dead - but the authorities also discovered four dead hostages at the market. Sixteen hostages were freed, one from the printing plant and 15 others from the store.
After the killings at the Charlie Hebdo offices, Cherif Kouachi, 32, and his 34-year-old brother Said led police on a chase around northeastern France, before ending up at the printing plant in Dammartin-en-Goele, near Charles de Gaulle airport.
Authorities said the brothers temporarily took a man hostage at the plant but let him go.
A member of the al Qaeda in the Arabian Peninsula gave a statement in English to The Associated Press saying the group's leadership "directed the operations and they have chosen their target carefully."
The attack was in line with warnings from the late al Qaeda leader Osama bin Laden to the West about "the consequences of the persistence in the blasphemy against Muslim sanctities," the member said, speaking on condition of anonymity because the group's regulations do not permit him to give his name.
The brothers were cornered there for much of the day before the explosions and gunfire rang out in the twilight and a police SWAT team clambered onto the roof.
"They said they want to die as martyrs," Yves Albarello, a local lawmaker inside the command post, told French television station, i-Tele.
At the kosher grocery near the Porte de Vincennes neighborhood of the capital, the gunman burst in shooting just a few hours before the Jewish Sabbath began, declaring "You know who I am," the official recounted.
The attack came before sundown when the store would have been crowded with shoppers, and Hollande called it "a terrifying anti-Semitic act."Coulibaly killed the four people in the market shortly after entering, Molins said.
Police officers investigate the scene after storming the kosher market, in Paris. (AP Photo)
Authorities increasingly grew to see links between the attackers after they discovered that Boumeddiene and the companion of one of the Kouachi brothers had exchanged about 500 phone calls, Molins said.
He added that several people have been given preliminary charges in the investigation. They include relatives of the three gunmen.
Minutes before police stormed both sites, Coulibaly had threatened more violence if authorities launched an assault on the two brothers, a police official said. A group of people holed up in the supermarket's freezer - apparently unbeknownst to the gunman.
In the final assault, phalanxes of security forces converged on the store entrance behind a flash from a stun grenade - and fired inside. Frenzied civilians - one of them carrying a toddler - scurried out under escort by helmeted police in body armor.
Police said Coulibaly had been a co-suspect with Cherif Kouachi in a court case involving terrorism that never made it to trial.
Cherif Kouachi was convicted of terrorism charges in 2008 for ties to a network sending jihadis to fight US forces in Iraq.
According to a Yemeni security official, Said Kouachi is suspected of having fought for al Qaeda in Yemen. Another senior security official added that Said was in Yemen until 2012.
Both officials spoke to the AP on condition of anonymity because of an ongoing investigation into Kouachi's stay in Yemen.
Both brothers were also on the US no-fly list, a senior US counterterrorism official said, speaking on condition of anonymity because the official was not authorized to discuss foreign intelligence publicly.The attacks in France as well as a hostage siege last month in Sydney and the October killing of a solder near Canada's parliament prompted the US state department to issue a global travel warning for Americans. It also cites an increased risk of reprisals against US and Western targets for the US-led intervention against Islamic State militants in Syria and Iraq.
People hold pencils and placards reading "I Am Charlie" (Je Suis Charlie) outside the Consulate of France in Barcelona during a tribute for victims of a terror attack on Charlie Hebdo. (AFP Photo)
Authorities around Europe have warned of the threat posed by the return of Western jihadis trained in warfare. France counts at least 1,200 citizens in the war zone in Syria - headed there, returned or dead. Both the Islamic State group and al Qaeda have threatened France, home to Western Europe's largest Muslim population.
The publication Charlie Hebdo had long drawn threats for its depictions of Islam, although it also lampooned other religions and political figures. It had caricatured the Prophet Muhammad, and a sketch of Islamic State's leader was the last tweet sent by the irreverent newspaper minutes before the attack.
Eight journalists, two police officers, a maintenance worker and a visitor were killed in the newspaper attack, including the paper's editor. Charlie Hebdo plans a special edition next week, produced in the offices of another paper.