The French leader told lawmakers at the Palace of Versailles in a special session last week that "The burkha is not a sign of religion, it is a sign of subservience." "It will not be welcome on the territory of the French republic," he told members of both Houses of parliament.

The comment sparked a racial row and was condemned by Islamists in many countries. Now militants of al Qaeda's North African network have called on French Muslims to react "with the utmost hostility".

"We will seek dreadful revenge on France by all means at our disposal, for the honour of our daughters and sisters," an Islamic extremist website was quoted as saying by the Mail online on Thursday.

"Our Mujahadin followers must not remain silent in the face of such provocation and such injustice," it said in a message.

French security are on "high level of vigilance" as authorities reaffirmed "their determination to fight terrorism". "Our security services will remain on their continuously high level of vigilance against any threat to security in France," a French government spokesman was quoted as saying by the British news portal.

France, which has Western Europe's largest Muslim population, enacted a law in 2004 banning the Islamic headscarf and other conspicuous religious symbols from public schools, triggering a racial row over the issue.

The commission of 58 French MPs is expected to announce its decision later this year on whether a law should be passed to ban the burkha.

France's Muslim Council said that the proposal "stigmatised" Islam and was a waste of time focusing on a fringe phenomenon.