A firebomb attack gutted the headquarters of French satirical weekly Charlie Hebdo on Wednesday after it put an image of the Prophet Mohammad (PBUH) on its cover.
This week's edition shows a cartoon of Mohammad and a speech bubble with the words: "100 lashes if you don't die of laughter". It has the headline "Charia Hebdo", in a reference to Muslim sharia law, and says Prophet Mohammad guest-edited the issue.
Charlie Hebdo's website on Wednesday appeared to have been hacked and briefly showed images of a mosque with the message "no God but Allah", after which the site was blanked.
Many Muslims object to any representation of Allah or Prophet Mohammad, or to irreverent treatment of the Qur'an, and such incidents have inflamed protests in the past, sometimes violent.
Danish cartoons of Prophet Mohammad in 2005 sparked unrest in the Muslim world in which at least 50 people were killed. An American pastor's burning of a copy of the Qur'an led to protests in Afghanistan in April in which several died.
Police said nobody was injured in the fire that broke out at about 1 am in the office building that houses Charlie Hebdo. Windows were broken on the ground floor and first floor and fire damage was visible inside. The Paris prosecutor's office said that two molotov cocktails had been thrown into the magazine's offices.
"The building is still standing. The problem is there's nothing left inside," Stephane Charbonnier, editor of Charlie Hebdo, told Europe 1 radio.
The main representative body of the Muslim faith in France, the French Muslim Council (CFCM), denounced the attack while also faulting the satirical publication.
"The CFCM deplores the deeply mocking tone of the newspaper towards Islam and its prophet, but reaffirms with force its total opposition to any act or form of violence," it said in statement.
About 5 million Muslims live in France, a country of about 65 million people.
Tareq Oubrou, head of the Association of Imams of France, also condemned the attack. "This is an inadmissible act," he told French TV station i>tele.
"Freedom is very important. It is nonetheless important to underline the sensitivity of the situation we face today.
"I call on Muslims to treat this lucidly and not succumb to what they consider as provocations regarding their religion ... I personally call on Muslims to keep an open mind and not take this too seriously."
In Dubai, the world's largest international Muslim body condemned Charlie Hebdo for publishing the image and a "highly provocative" editorial, but urged restraint among Muslims.