Updated

French magazine Charlie Hebdo will mark the anniversary of an Islamist attack on its Paris offices with an edition featuring an armed man representing God on the cover.

The publication on Wednesday will be accompanied by the headline "1 An Apres - L'Asssassin Court Toujors" (One Year Later: The Assassin Is Still Out There).

The attack last Jan. 7 carried out by two Islamic militants in revenge for cartoon depictions in the magazine of the Muslim prophet Mohammed left 12 people dead.

Brothers Said and Cherif Kouachi forced their way into the building with assault rifles, killing 11 people and injuring 11 more. Upon leaving the building they also shot dead a French police officer.

The pair shouted "Allahu akbar" (God is great) during the assault and were later killed in a shoot-out with police during a stand-off on an industrial estate 18 miles northeast of Paris.

One million copies of the anniversary edition featuring a collection of cartoons by five of the magazine's cartoonists killed in the attack will be distributed for sale in French newsstands, with thousands more exported for sale overseas.

Cartoonist Laurent Sourisseau, who took over the magazine's management following the attack, has written a robust defence of secularism which denounces what he calls "fanatics brutalised by the Koran".

Mr Sourisseau, who was seriously wounded in last year's attack, also takes a swipe at what he describes as those from other religions who hoped for the death of the magazine for "daring to laugh at the religious".

Prior to the attack the magazine's employees received death threats for publishing cartoons featuring Mohammed, and its offices were firebombed in 2011.

Sales fell below 30,000 a week and the magazine was close to shutting down.

But the assault caused revulsion around the world and 7.5 million people bought the magazine's post-attack issue in support of the idea that Islam should not be protected from satire.