France put into motion Monday the world's first ban on Islamic face veils, meaning that women may bare their breasts in Cannes but not cover their faces on the Champs-Elysée.

Two veiled women were hauled off from a Paris protest just hours after the ban came into effect. Their unauthorized demonstration, on the cobblestone square facing Notre Dame Cathedral, was rich with both the symbolism of France's modern spirit of defiance and its medieval history.

While some see encroaching Islamophobia in the new ban, President Nicolas Sarkozy's government defended it as a rampart protecting France's identity against inequality and extremism. Police grumbled that it will be hard to enforce.

"The law is very clear. Hiding your face in public places is cause for imposing sanctions," Interior Minister Claude Guéant said Monday at an EU meeting in Luxembourg. He said it defends "two fundamental principles: the principle of secularism and the principle of equality between man and woman."

Two of the veiled women were taken away by police for taking part in an unauthorized demonstration, Paris police authority said. They were released later Monday after questioning.

Amnesty International condemned the detention of the two women and others at the protest.

It was unclear whether the women were also fined for wearing a veil.

Kenza Drider, a French Muslim of North African descent, wearing a niqab, is seen outside the Notre Dame Cathedral in Paris on Monday. (Gonzalo Fuentes/Reuters)

The law says veiled women risk a 150-euro ($210 Cdn) fine or special citizenship classes, though not jail. People who force women to don a veil are subject to up to a year in prison and a 30,000-euro ($41,000) fine, and possibly twice that if the veiled person is a minor.

The ban affects women who wear the niqab and the burka. The law is worded to skate safely through legal minefields: The words "women," "Muslim" and "veil" are not even mentioned. The law says it is illegal to hide the face in the public space, but makes exceptions to allow for motorcycle helmets, traditional ceremonies such as weddings or Carnival costumes.

While Italy also has a law against concealing the face for security reasons, France's law was the first conceived to target veil-wearers. Sarkozy said he wanted a ban, and that the veils are not welcome in France.

Though only a very small minority — 2,000 women at most — of France's five million Muslims wear the veil, many Muslims see the ban as an affront to the country's No. 2 religion.

Freelance reporter Genevieve Oger told CBC News from Paris that veiled women in France are rarely seen outside of a few high-immigration areas.

"If you expect to see them walking down the street in France, that's actually really quite rare," she said. "As a result, a lot of people are saying that this law is really just only symbolic and that it won't have any great impact."

About a dozen people, including three women wearing niqabs with just a slit for the eyes, staged a protest in front of Notre Dame on Monday, saying the ban is an affront to their freedom of expression and religion.

Much larger crowds of police, journalists and tourists filled the square.

Oger said that in many cases the women are young, French-born daughters of immigrants who have a "spiritual reawakening" and become more religious than their family, wearing the veil as an identity statement — often over the objections of their parents.

The ban affects women who wear the niqab, which has just a slit for the eyes, and the burka, which has a mesh screen over the eyes.

Kenza Drider, who lives in Sauvignon and wears a niqab, calls the ban racist.

Veiled Muslim women in London take part in a protest against France banning the wearing of Islamic veils on Monday. Matt Dunham/Associated Press

Right before the ban came into effect, she told The Associated Press she would continue to go "shopping, to the post office and to city hall if necessary."

"I will under no circumstance stop wearing my veil. If I am warned verbally and must appear before the local prosecutor.… I will appeal to the European Court of Human Rights."

The veil, for her, "is a submission to God," Drider said.

The ban had strong support from France's leading parties on left and right in a country that separated church and state with a 1905 law but has struggled in recent years to integrate a growing Muslim population.

Police on Saturday arrested 61 people — including 19 women — for attempting to hold an outlawed Paris protest against France's pending ban on face-covering Islamic veils.

Moderate Muslim leaders in France and elsewhere agree that Islam does not require women to cover their faces, but many are uncomfortable with banning the veil. Religious leaders have denounced the measure, and are struggling with what to advise the faithful.

'It's not a racist law.... You need to accept it if you want to integrate into France and with French people'— Laurent Berrebe, Paris resident

The plans for a ban prompted protests in Pakistan last year and warnings from al-Qaeda. It also has devout Muslim tourists skittish, since it applies to visitors as well as French citizens.

Public opinion in Paris on the morality of enforcing the ban appears mixed.

"It's not a racist law. It's just a law that is coming from the history of France and so you need to accept it if you want to integrate into France and with French people," insisted Laurent Berrebe, an economist walking in central Paris on Monday.

Nurse Olfa Belmanaa is opposed.

"We are in France, we are in a democratic country where everyone has the right to do what they want. If they want to wear a veil or go completely nude that's their right."

With files from CBC News