A French satirical magazine published nude cartoons of the Prophet Mohammed Wednesday, a move that could further inflame tensions after violent protests in the Muslim world over an anti-Islam film.
The cover of Charlie Hebdo shows a Muslim in a wheelchair being pushed by an Orthodox Jew under the title "Intouchables 2", referring to an award-winning French film about a poor black man who helps an aristocratic quadriplegic.
Another cartoon on the back page of the weekly magazine show a naked turbaned Mohammed exposing his posterior to a film director, a scene inspired by a 1963 film starring French film star Brigitte Bardot.
France has stepped up security at its embassies in countries following the move, Foreign Minister Laurent Fabius said Wednesday.
"I have obviously issued instructions so that special security measures are taken in all the countries where this could pose a problem," Fabius said, admitting that he was "concerned" by the potential for a backlash.
The publication came a day after 12 died in an Afghan suicide bombing, the deadliest attack linked to an anti-Islamic film.
A female suicide bomber killed 12 people in Afghanistan on Tuesday in the deadliest single attack attributed to the controversial film which has sparked furious protests across the Muslim world.
The deaths raised to over 30 the toll from incidents linked to the trailer for "Innocence of Muslims," a film produced by extremist Christians in the United States that depicts the Prophet Mohammed as a thuggish womaniser.
Charlie Hebdo's website crashed on Wednesday after being bombarded with comments that ranged from hate mail to approbation.
The magazine is no stranger to controversy over issues relating to Islam.
Last year it published an edition "guest-edited" by the Prophet Mohammed that it called Sharia Hebdo. The magazine's offices in Paris were subsequently fire-bombed.
French Prime Minister Jean-Marc Ayrault said anyone offended by cartoons could take the matter to the courts after expressing his "disapproval of all excesses".
But he emphasised France's tradition of free speech. "We are in a country where freedom of expression is guaranteed, including the freedom to caricature," he said on RTL radio.
"If people really feel offended in their beliefs and think there has been an infringement of the law -- and we are in a state where laws must be totally respected -- they can go to court," Ayrault said.
He also said a request to hold a demonstration in Paris against the controversial US-made anti-Islam film "Innocence of Muslims" which has sparked furious protests across the Muslim world would be refused.
Charlie Hebdo's latest move was greeted with immediate calls from political and religious leaders for the media to act responsibly and avoid inflaming the current situation.
The magazine's editor, originally a cartoonist who uses the name Charb, denied he was being deliberately provocative at a delicate time.
"The freedom of the press, is that a provocation?" he said. "I'm not asking strict Muslims to read Charlie Hebdo, just like I wouldn't go to a mosque to listen to speeches that go against everything I believe."
Dalil Boubakeur, the senior cleric at Paris's biggest mosque, appealed for France's four million Muslims to remain calm.
"It is with astonishment, sadness and concern that I have learned that this publication is risking increasing the current outrage across the Muslim world," he said.
"I would appeal to them not to pour oil on the fire."
France's Muslim Council, the community's main representative body, also appealed for calm in the face of "this new act of Islamaphobia".
President Barack Obama said Tuesday he expected governments in the Muslim world to protect American diplomats, despite their revulsion at a film made on US soil deemed offensive to their faith.
"The message we have to send to the Muslim world is that we expect you to work with us, to keep our people safe," Obama said during a taping of the "Late Show with David Letterman" on CBS TV.
US Secretary of State Hillary Clinton, meanwhile, said "we are taking aggressive steps to protect" diplomatic missions worldwide.
Among those killed so far have been four US diplomatic staff in Libya, including ambassador Chris Stevens, who died when militants laid siege to the US mission in Benghazi a week ago on September 11 in a four-hour attack.
Clinton said the FBI had launched an investigation inside Libya, and she vowed that "we will not rest until the people who orchestrated this attack are found and punished."
In Afghanistan, Hezb-i-Islami, the second largest insurgent group after the Taliban, said the suicide bomb attack was to avenge the "insult" of the film.
"The bombing was in retaliation for the insult to our Prophet," spokesman Zubair Sidiqi told AFP by phone from an undisclosed location.
Security officials said nine foreigners including South Africans were among those killed on a highway leading to Kabul airport when the bomber blew up her station wagon alongside a minivan carrying foreign workers.
Taliban fighters last week stormed a British-run airfield, killing two US Marines and destroying six US fighter jets in another act of vengeance.
In Lebanon, the head of the Shiite Muslim movement Hezbollah, listed in the United States as a terrorist organisation, made a rare public appearance to warn of "very dangerous" repercussions if the entire film is released, rather than the 14-minute trailer that has already sparked outrage.
Al-Qaeda's franchise in North Africa urged Muslims to storm US embassies and kill American envoys in Muslim countries, monitoring group IntelCenter said.
The film-maker Nakoula Basseley Nakoula, a 55-year-old Egyptian Copt and fraudster who was sentenced to 21 months in prison in the United States in June 2010, has not been seen since Saturday when he was questioned.
The risks now facing those involved in the film's production were underlined when a Salafist cleric in Egypt called Monday for the deaths of all those involved in its making.
Before dawn on Monday, officers from the Los Angeles County sheriff's department escorted four members of Nakoula's family to join him in hiding.
Egypt's public prosecutor has ordered that seven US-based Egyptian Copts be tried over their role in the film, accusing them of "insulting the Islamic religion, insulting the Prophet and inciting sectarian strife."
However Interpol in a statement said it was not aware of any request from Egypt for the arrest of people related to the film but stressed that its charter "forbids it from undertaking any matter of a predominantly political, military, religious or racial nature."
In Pakistan, two protesters died after demonstrating against the film close to the Afghan border and outside the US consulate in Karachi.
Police used tear gas to disperse more than 2,000 protesters trying to reach the US consulate in the city of Peshawar, chanting anti-US slogans and burning the Stars and Stripes flag.