12 people have been shot dead at the Paris office of French satirical magazine Charlie Hebdo in an apparent militant Islamist attack, and a manhunt is underway for 3 gunmen.
How events unfolded...taken from LIVE COVERAGE
Dublin demo - In another display of solidarity, dozens of Ireland's French community have gathered in Dublin's O'Connell Street. Some are holding "Je suis Charlie" posters and "Charlie" is spelt out in candles, echoing scenes in Paris.
"What happened in France today was outrageous, and all of us French people are very affected by it," says Juliet Pigeaud-Fabre, who is studying in Dublin. "I am studying journalism so it's kind of freaky what happened and I know people affected by the tragedy."
"I'm French and I feel like someone just punched me in the face and I feel this is going to trigger a load of violence. It's crazy and it's horrible," says Louis, 18. "It's not just a French problem. It's a global issue and it's something we will all have to deal with."
Obama pledges support - US President Barack Obama has condemned the "cowardly, evil" assault and pledged US assistance to Paris to bring the attackers to justice. Speaking from the Oval Office he said: "France is one of our oldest allies, our strongest allies.
"For us to see the kind of cowardly, evil attacks that took place today, I think, reinforces once again why it's so important for us to stand in solidarity with them, just as they stand in solidarity with us.
"The fact that this was an attack on journalists, attack on our free press, also underscores the degree to which these terrorists fear freedom -- of speech and freedom of the press," he added.
100,000 rally - As night falls in France, more than 100,000 people are gathered in cities around the country to pay tribute to the victims of the Charlie Hebdo attack and defend free speech.
In Paris 35,000 are gathered Place de la Republique, not far from where the attack took place, police say. Officials in cities such as Marseille, Toulouse and Lyon also reported thousands gathering in public spaces on the country's darkest day in decades.
'Suffering together' - Demonstrator Coline Fillonneau tells AFPTV:"I think it's important for everyone, it's France which suffered today, but it's not just us, it's the whole world. I think everyone in France was attacked today. It's about liberty, it's important for every Frenchman so it's important for the whole world."
Another, Arnaud Baecher says: "It's important that the people who did this see that we express ourselves, we even laugh, and cry, we are all here together and this won't stop us."
'Not afraid' - Crowds in the square are chanting "We are not afraid, Charlie" while some have come with big luminous letters that read "N.O.T A.F.R.A.I.D"
Others chant "Charlie brotherhood" as huge black and white portraits of Cabu and Tignous, two of the victims of the attack, are displayed by protesters.
Muslim protester - Back at the Place de la Republique in Paris, Chiheb Bouanene, a Tunisian painter from Champigny (Val de Marne) , holds a placard reading: "I am Muslim, I am Charlie Hebdo".
"Or course, freedom of the press should come before all else. I jumped in my car and I came immediately with my three friends. I read Charlie from time to time. I often don't agree with them, but freedom of the press comes before all else."
MORE THAN 100,000 RALLY ACROSS FRANCE AFTER ATTACK
London demo - In solidarity with demonstrators in France, crowds have gathered in London's Trafalgar Square, many of them carrying placards bearing the slogan "je suis Charlie" which has flooded social media sites during the day in response to the attack.
AFP reporter Edouard Guihaire says several hundred people are assembled, faces sombre, many of them French.
"I heard the news this morning. Like everyone, I was deeply affected by it," says Frenchman Nabil Nadifi, 29, who has been living in the British capital for a few months.
Day of mourning - More on the announcement from Hollande that Thursday will be a day of mourning: speaking in a televised address he says flags will fly at half-mast across the country for three days.
"Unity is our best weapon.... Freedom will always be stronger than barbarity," he tells the nation.
HOLLANDE SAYS THURSDAY TO BE DAY OF MOURNING IN FRANCE AFTER ATTACK
'Charlie must not die' - As well as a huge demonstration at the Place de la Republique in Paris, around 2,500 people are gathered at the Place d'Armes in Metz, northeastern France, reports AFP's Jean-Luc Chandelier.
Jean Lambert, of local LGBT (Lesbian, gay, bisexual, and transgender) association Gay Colours, struggles to hold back tears as he tells AFP: "We had regular contact with Charlie Hebdo, they always supported us."
Wearing a t-shirt with the names of the magazine staff killed in the attack, he adds: "They were part of my politics, with their insolence, their freedom. It's a limb that has been torn from me. Charlie must not die."
Pope reacts - Pope Francis has strongly condemned the "horrible attack" on the French magazine. Vatican spokesman Federico Lombardi says: "The Holy Father expresses the strongest condemnation for the horrible attack that plunged the city of Paris into mourning."
Saudi 'sorrow' - Saudi Arabia, the home of Islam's holiest sites, says the killings in France are incompatible with the Muslim religion.
"The Kingdom of Saudi Arabia has followed with deep sorrow the terrorist attack" at the Charlie Hebdo magazine, the state Saudi Press Agency says, citing an unnamed official source.
It said the source condemned "this cowardly terrorist attack which is incompatible with Islam".
'Republic in danger' - Adrien Tiberti, of the PCF (French Communist Party), among the demonstrators in the central Paris square, tells AFP: "We hare here because the Republic is in danger.... It is extremely serious... This has been a real blow. Coming together is a way of overcoming that."
Fellow PCF member Isabelle Charpentier adds: "If we must demonstrate every day, we will demonstrate every day. No one deserves to die for his ideas."
Crowds in the Place de la Republic chant "Charlie, Charlie, Charlie" and vocalise the slogans seen on banners defending "freedom of speech, freedom of thought", says AFP's Rebecca Frasquet. There are also renditions of the French national anthem, La Marseillaise.
Charb - Charbonnier, also known as Charb, took over the running of Charlie Hebdo in 2009 after joining its staff in 1992. His irreverent caricatures of politicians and other figures mostly appeared in the publication, but also popped up in many other left-wing outlets and outright comics.
He had been living under police protection after receiving death threats for Charlie Hebdo's run of a Mohammed cartoon in 2011, which also saw the newspaper firebombed and its website hacked.
Free speech - Many people are waving placards, some bearing a quote by Stephane Charbonnier -- the editor of Charlie Hebdo killed in the attack -- which has been much repeated during the day on social media: "I prefer to die standing than live on my knees"
Other banners hail "freedom of expression" and "freedom of thought".
Place de la Republique - Huge crowds of people are gathered at Place de la Republique in central Paris. AFP reporters estimate the numbers at more than 10,000.
"There are delegations from the CGT, Unsa, and Solidaire unions and the PCF (French communist party) Some old, some young, a huge melting pot," says AFP's Stephane Jourdain.
GMT - THOUSANDS JOIN RALLIES IN FRANCE TO PAY TRIBUTE TO PARIS ATTACK VICTIMS
Car hijacking - Earlier we reported that the gunmen fled in a black Citroen car. They later abandoned this car at Porte de Pantin in eastern Paris, before hijacking another car and fleeing towards the north of the capital, where authorities lost the trail.
Round-up - For anyone just joining us, here is a brief summary of today's dramatic events in Paris where 12 people were killed in a gun attack on a satirical magazine.
-- Heavily armed gunmen stormed the offices of Charlie Hebdo, a publication that has outraged Muslims with controversial cartoons of the Prophet Mohammed at around 11:20 am local time.
-- Attackers opened fire with assault rifles on staff gathered for an editorial meeting. Among those killed were three cartoonists and the chief editor as well as a police officer.
-- A second police officer was shot dead as masked attackers fired at police in the street before fleeing by car. Police said witnesses heard the gunmen shout "we have avenged the prophet" and "Allahu Akbar" (God is greatest).
-- France's Interior Minister said security services were hunting three "criminals". President Francois Hollande, who immediately rushed to the scene, branded the attack "an act of exceptional barbarism" as world leaders united in condemnation.