Governments around Europe huddled with their intelligence services Wednesday to evaluate security measures in the wake of the massacre at French satirical weekly Charlie Hebdo.

The Paris attack by heavily armed masked men shouting "Allahu akbar" (God is Greatest) was the worst in France in decades and stoked fears of a new wave of Islamist attacks in Europe.

Long before being targeted in Wednesday's massacre in Paris, satirical newspaper Charlie Hebdo had been considered high on the potential hit-list for jihadists calling for strikes in the heart of Europe.

When Charlie Hebdo defiantly republished already controversial cartoons of the Prophet Mohammed considered sacrilegious by Muslims in 2006, it knew it was taking a risk.

Lebanese officials and political leaders condemned Wednesday the attack on the Paris offices of the French satirical weekly Charlie Hebdo, which left 12 people dead, saying the incident was not only an assault against France but also against Islam itself.

Prime Minister Tammam Salam sent a cable to French President Francois Hollande, condoling him over the victims and expressing “the solidarity of the Lebanese people with France.”

It was like something out of a movie: gunfire, tires screeching, police sirens and "rivers of blood" as terror descended on a nondescript building in a calm Parisian street.

Annick Chevalier, 50, was at work assisting the elderly near the headquarters of French satirical magazine Charlie Hebdo when she heard what she thought were fireworks.

The massacre Wednesday at French weekly Charlie Hebdo took place after years of confrontation between the satirical publication and Islamists infuriated by what they see as its attacks on their religion.

Its offices were fire-bombed in November 2011 when it published caricatures of the Muslim prophet Mohammed but there were no casualties in that attack.

An Islamist militant considered one of the main recruiters of foreigners to the jihadist fight against government forces in Syria was convicted in absentia to three years in prison in France on Wednesday.

Algerian Said Arif, who was previously convicted in 2007 in France for terrorist-related activities, was sentenced to three years in prison by a court in central France for crimes stemming from his flight from house arrest in January 2012. 

Gunmen killed 12 people in an attack Wednesday in the offices of the French satirical weekly Charlie Hebdo, the worst such attack in France in at least 40 years.

Here is a rundown of previous major attacks.

U.S. President Barack Obama led global condemnation of the shooting at a French magazine on Wednesday which left 12 people dead, with world leaders and media groups branding it an act of terror and an attack on free speech.

U.N. Secretary General Ban Ki-Moon and Queen Elizabeth II also offered their sympathy, after masked men armed with Kalashnikov automatic rifles opened fire at the offices of satirical weekly Charlie Hebdo in Paris.

Heavily armed men shouting "Allahu akbar" stormed the Paris headquarters of a satirical weekly on Wednesday, killing 12 people in an attack that brought more than 100,000 protesters onto streets across France. 

The assault on the Charlie Hebdo headquarters, the worst attack in France in decades, sparked a massive manhunt as the two gunmen in black commando gear escaped, executing a wounded police officer with a shot to the head.

Ukraine said on Wednesday three of its soldiers were killed in a spate of Orthodox Christmas Eve attacks by pro-Russian insurgents in the former Soviet republic's industrial east.

The deaths bring to more than 20 the number of Ukranian troops killed since the warring sides signed a reinforced truce deal on December 9.