France's ban on face veils, a first in Europe, went into force on Monday, and anyone wearing the niqab or burqa in public could now face a fine of €150 (£132), or lessons in French citizenship.
The centre-right government, which passed the law in October, has rolled out a public relations campaign to explain the ban and the rules of its application that includes posters, pamphlets and a government-hosted website.
Guidelines spelled out in the pamphlet forbid police from asking women to remove their burqa in the street. They will instead be escorted to a police station and asked to remove the veil there for identification.
Widely criticised by Muslims abroad as impinging on their religious freedom, the law has provoked a limited backlash in France where a strict separation of church and state is seen as central to maintaining a peaceful civil society.
A property dealer is urging women to engage in "civil disobedience" by continuing to wear the veil if they so desire and has called on supporters to hold a silent prayer in protest at the ban in front of Notre Dame cathedral. Rachid Nekkaz, who is a Muslim, said in a webcast he would help pay fines and was putting a property worth around €2m up for sale to fund his campaign.
"The street is the universal home of freedom and nobody should challenge that so long as these woman are not impinging on anyone else's freedom," he said. "I am calling on all free women who so wish to wear the veil in the street and engage in civil disobedience," he said.
In Avignon, Vaucluse, Reuters TV filmed a woman boarding a train wearing a niqab, unchallenged by police.
"It's not an act of provocation," said Kenza Drider. "I'm only carrying out my citizens' rights, I'm not committing a crime ... If they [police] ask me for identity papers I'll show them, no problem."
France has five million Muslims, but fewer than 2,000 women are believed actually to wear a face veil.
Many Muslim leaders have said they support neither the veil nor the law banning it.
On Saturday, French police arrested around 60 people who turned up for a banned protest over the veil ban which had been called by a Muslim group in Britain. One of the protesters was arrested on his arrival from Britain, a police spokesman said.
The timing is all the more sensitive after France's ruling UMP party called a debate on the role of Islam in French society, a forum that some criticised as unfairly singling out a portion of the population as problematic.
The guide sent out last week to police notes that the burqa ban does not apply inside private cars, but it reminds officers that such cases can be dealt with under road safety rules.
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