PARIS (REUTERS, AFP) – A raid by France’s elite anti-terrorist unit was under way in the north-eastern city of Reims as part of the hunt for the gunmen who attacked the satirical newspaper Charlie Hebdo.

Either the suspects will be able to escape, or “there will be a showdown”, said a member of the unit, urging journalists at the scene to remain “vigilant”.

Police are hunting three French nationals, including two brothers from the Paris region, after suspected Islamist gunmen killed 12 people at a satirical magazine on Wednesday, a police official and government source said.

Bloomberg news, quoting Le Point, identified the assailants as brothers Said and Cherif Kaouchi, aged 32 and 34, and Hamyd Mourad, 18. Police source said one of the brothers had previously been tried on terrorism charges.

The hooded attackers stormed the Paris offices of Charlie Hebdo, a weekly known for lampooning Islam and other religions, in the most deadly militant attack on French soil in decades.

Famous French cartoonists Cabu, Charb, Tignous and Wolinski were killed in the attack. Charb, or Stephane Charbonnier, was the publishing editor of the magazine. The attack took place during the weekly’s editorial meeting, when all the journalists were supposed to be present, according to a France TV source.

Another 20 people were injured in the attack, including four or five critically.

French Interior minister Bernard Cazeneuve said three gunmen were involved in the attack, and that all measures were being taken “to neutralise these three criminals who have committed this barbaric act”. One of the men was captured on video shouting “Allah!” as four shots rang out. Two assailants were then seen calmly leaving the scene. A police official said the gunmen fled towards the eastern Paris suburbs.

A short amateur video broadcast by French television stations shows two hooded men outside the building. One of them sees a wounded policeman lying on the ground and strides over to him to shoot him dead at point-blank range. The two then walk over to a black saloon car and drive off.

In another clip on Television station iTELE, they are heard shouting: “We have killed Charlie Hebdo. We have avenged the Prophet Mohammad.”

A video purportedly showing the gunmen was posted on YouTube. (WARNING: Video is graphic in nature. Viewer discretion is advised)

Charlie Hebdo (Charlie Weekly) is well known for courting controversy with satirical attacks on political and religious leaders and has published numerous cartoons ridiculing the Prophet Muhammad. The last tweet on its account mocked Abu Bakr al-Baghdadi, the leader of the militant Islamic State, which has taken control of large swathes of Iraq and Syria.

French President Francois Hollande rushed to the scene. “An act of indescribable barbarity has just been committed today in Paris,” he said. “Measures have been taken to find those responsible, they will be hunted for as long as it takes to catch them and bring them to justice.”

Sirens could be heard across Paris as Prime Minister Manuel Valls said security would be ramped up at transport hubs, religious sites, media offices and department stores. French schools, consulates and cultural centres in 20 Muslim countries were briefly closed along with embassies for fear of retaliatory attacks.

‘These guys were serious’

Police union official Contento described the scene inside the offices as “carnage”.

A source close to the investigation said two men “armed with a Kalashnikov and a rocket-launcher” stormed the building in central Paris and “fire was exchanged with security forces”. The source said gunmen had hijacked a car and knocked over a pedestrian as he sped away.

Dozens of police and emergency services were at the site as police secured a wide perimeter around the shooting site, where a Reuters reporter saw a car riddled with bullet holes.

Witness Benoit Bringer told TV station iTELE: “About a half an hour ago two black-hooded men entered the building with Kalashnikovs (rifles). A few minutes later we heard lots of shots.”

One man, who witnessed the attack, described a scene like “in a movie”. “I saw them leaving and shooting. They were wearing masks. These guys were serious,” said the man who declined to give his name. “At first I thought it was special forces chasing drug
traffickers or something.”

An employee at a nearby daycare center said he was walking with children when panic erupted. “People leaned out of the window and yelled at me to get off the pavement,” he said. “We got out of there very fast,” said Jean-Paul Chevalier, 56. “People were panicking. I heard shooting.”

A tweet from journalist Martin Boudot who was reportedly sheltering on the roof with his colleagues. The tweet reads: “Attack by two hooded men on the offices of Charlie Hebdo. We’ve taken refuge on the roof”. — @MARTINBOUDOT/TWITTER

This tweet, by Le Monde journalist Elise Barthet, appears to show two gunmen pointing their weapons at a police car.

Death threats

Charlie Hebdo gained notoriety in February 2006 when it reprinted cartoons of the Prophet Muhammed that had originally appeared in Danish daily Jyllands-Posten, causing fury across the Muslim world. Its offices were fire-bombed in November 2011 when it published a cartoon of Muhammed under the title “Sharia Hebdo”.

Despite being taken to court under anti-racism laws, the weekly continued to publish controversial cartoons of the Muslim prophet. In September 2012, Charlie Hebdo published cartoons of a naked Muhammed as violent protests were taking place in several countries over a low-budget film, titled “Innocence of Muslims”, which was made in the United States and insulted the prophet.

Editor-in-chief Charbonnier had lived under police protection after receiving death threats.

The paper’s last tweet on Wednesday morning before the attack included a cartoon of Islamic State group leader Abu Bakr al-Baghdadi and Happy New Year wishes.

This week’s front page featured controversial author French Michel Houellebecq, whose latest book “Soumission”, or “Submission,” which imagines a France in the near future that is ruled by an Islamic government, came out Wednesday. The book has widely been touted as tapping into growing unease among non-Muslim French about immigration and the rise of Islamic influence in society.

Countries condemn attack

The attack took place at a time of heightened fears in France and other European capitals over fallout from the wars in Iraq and Syria, where hundreds of European citizens have gone to fight alongside the radical Islamic State group. In a sign of such tensions, a media group’s office in Madrid was evacuated later in the day after a suspicious package was sent there.

France last year reinforced its anti-terrorism laws and is already on alert after calls from Islamist militants to attack its citizens and interests in reprisal for French military strikes on Islamist strongholds in the Middle East and Africa.

US President Barack Obama has condemned the deadly shooting, calling it a terrorist attack against its ally. “We are in touch with French officials and I have directed my administration to provide any assistance needed to help bring these terrorists to justice,” he said in a statement.

German Chancellor Angela Merkel was among European leaders condemning the shooting. “This abominable act is not only an attack on the lives of French citizens and their security. It is also an attack on freedom of speech and the press, core elements of our free democratic culture.

British Prime Minister David Cameron said Britain stood with its ally against “all forms of terrorism”. Earlier, Cameron said in a Twitter message that the killings were “sickening”, while Foreign Secretary Philip Hammond said he was “appalled” to hear about the “apparent terrorist attack”.

The head of the French Muslim Council has called the attack a “declaration of war”. “It’s a thunderous declaration of war,” Mr Dalil Boubakeur, who is also imam of the mosque of Paris, was quoted as saying by Le Figaro newspaper. “The times have changed. We’re entering a new phase of this confrontation,” he said.

Another imam of the greater Paris region also expressed his outrage over the shooting. Said Mr Hassen Chalghoumi, imam of the Drancy mosque in Paris’s Seine-Saint-Denis northern suburb: “I am extremely angry. These are criminals, barbarians. They have sold their soul to hell. This is not freedom. This is not Islam and I hope the French will come out united at the end of this.”