France was on high alert Wednesday after a Paris-based satirical magazine published caricatures mocking the Muslim Prophet Mohammad.

It happened at a tense moment, with the past seven days seeing protests in Muslim countries over an amateurish video, made in the United States that ridicules the prophet. The American Ambassador to Libya, Christopher Stevens, and three other Americans were killed during one protest, last week.

The French magazine Charlie Hebdo not only mocks Mohammad, it also makes fun of the recent anti-American protests over the online video. Stephane Charbonnier, Charlie Hebdo’s editor, says that just as with the Danish caricatures of Mohammad back in 2005, it’s his right, even duty, to publish these 20 cartoons, offensive or not.

“If we start saying we can’t do these cartoons because there’s a risk someone will be shocked, then we’ll back down from publishing other cartoons,” he said to BBC, “because there always will be pressure for something less offensive, and so on and so on until we stop making them altogether.”

Charlie Hebdo has been lampooning all sorts of people for more than 20 years. Name someone famous or iconic and chances are they’ve been skewered — the Pope, Jesus Christ, politicians of all stripes and now, once again, Muhammad.

“This isn’t any more of a provocation than usual,” Charbonnier said. “It depends on who is on the other side, reading it. I don’t think that our regular readers are shocked. I think people who don’t read us, they’re shocked when they see the paper.”

Charlie Hebdo’s Muhammad caricatures run from mild political jabs to vulgar depictions of the prophet, naked.

Dalil Boubakeur, the head of the mosque of Paris, says the idea that someone would create and publish such images is “beyond comprehension.” It goes against normal reasoning, he says. It’s an abdication of responsibility.

The French government has sent riot police to protect the Paris offices of Charlie Hebdo. Overseas, French officials have a wary eye on this Friday’s Muslim prayers, and the possibility that protests could erupt.

France’s foreign minister, Laurent Fabius, said on Wednesday he’s implemented special security measures in countries where this could pose a problem. France is temporarily closing schools and embassies in some 20 countries. Fabius said it’s dangerous and sometimes irresponsible, when we know the general climate, to pour “oil on the fire.”

Fabius was referring to the sometimes violent protests against the U.S. and other Western countries over the online video depicting Muhammad as a dolt and a womanizer.

But other French officials are insisting that though the caricatures may be offensive and may provoke protest, they’re not illegal.

After a meeting with French Muslim leaders in Paris, Interior Minister Manuel Valls told reporters that caricatures, even of Muhammad, are protected by the fundamental right to free expression, even if they’re shocking.

“If anyone wants to pursue the matter, we have the courts,” he said.

Many Muslims around the world have condemned the use of violence to respond to insults. Meantime, Islamic extremists in some places have been trying to stir up Muslim anger and use it to their political advantage. This isn’t limited to the Muslim world, though.

In France, Marine Le Pen, the leader of France’s far right National Front, said on Wednesday that Charlie Hebdo embodied French values. She used the opportunity to invite anyone who doesn’t agree to leave France now.