A controversial ban on face veils has come into force in France, meaning anyone wearing the Muslim niqab or burqa in public will face a fine of up to $216 and a citizenship course.
Two protesters wearing niqab veils were arrested by police on Monday, after they took part in a demonstration outside Notre Dame cathedral in Paris, the capital.
However police said the pair were arrested for taking part in an unauthorised demonstration, not for wearing the veil.
Rachid Nekkaz, a property dealer who is offering to sell a building worth millions to fund a campaign against the ban, had urged people to go to Notre Dame cathedral for a silent prayer.
"I am calling on all free women who so wish, to wear the veil in the street and engage in civil disobedience," he said earlier.
Around a dozen people, including three women wearing the niqab, took part in the action, which was followed by a much larger crowd of journalists, police and onlookers.
One of those arrested outside the cathedral was Kenza Drider, a 32-year-old woman, who had earlier defied the ban by boarding a train from Avignon in the south to the demonstration in Paris.
"I had been invited to take part in a television programme which I am going for and I find that today is April 11, the first day of the application of the ban," she said earlier.
"This law infringes my European rights, I cannot but defend them that is to say my freedom to come and go and my religious freedom," the voluntary worker said.
Her husband Allal added: "According to this law, my wife would have to remain cloistered at home. Do you find that normal? She has been wearing a veil for 13 years and it has not shocked anyone".
France's five-million-strong Muslim minority is Western Europe's largest, but fewer than 2,000 women are believed to wear a full face veil.
It is the first European country to bring in a ban on face-covering veils. Neighbouring Belgium has passed a similar bill but is yet to enforce it, while in the Netherlands, far-right leaders have proposed a ban.
Many Muslim leaders have said they support neither the veil nor the law banning it, saying that it is not a religious practice but a cultural practice.
The French government says wearing the veil is a symbol of male oppression.
But rights groups have accused the government of Nicolas Sarkozy, the president, of attempting to stir up racial tensions and of targeting one of France's most vulnerable minorities.
Other groups have also accused Sarkozy of enforcing the law in order to try and win votes, Tim Friend, Al Jazeera's correspondent in Paris, said.
"There's an accusation against Sarkozy that he's trying to win back votes by introducing in this law in the face of increased support for anti-immigration parties in France.
"Many feel that this is not necessarily stricly about emphasising France's secular traditions but more a vote-winning exercise by Sarkozy, in other words, pandering to people's prejudices," he said.
How the law will be enforced has also come under question, since police officers will not be allowed to remove a woman's face covering.
In a guide sent out last week, police were told that the ban does not apply inside private cars as such cases can be dealt with under road safety rules.
Officers will be able to take anyone refusing to lift the veil to a police station, where they would be threatened with fines.
Those who are found guilty of forcing women to wear the face veil will also be prosecuted, facing a fine of up to $43,400.
The timing is all the more sensitive after UMP, the French ruling party, called a debate on the place of Islam in France. Some say that this move risks stigmatising a portion of the population.
French police arrested 59 people on Saturday who turned up for a banned protest over the veil ban, one of them on arrival in France from Britain, according to a police spokesman.