Secure-zone clearance has been withdrawn for nearly 70 people working at two Paris airports following the November 13 terror attacks on the French capital, the boss of the airports company said Sunday.

So-called red badges are issued to people employed in the secure zone of Roissy-Charles de Gaulle and Orly airports, working for instance as baggage handlers, aircraft cleaners and suppliers.

France's far-right National Front (FN) is aiming to win control of a region for the first time in its history in elections on Sunday, giving leader Marine Le Pen a launchpad for her presidential bid in 2017.

The anti-immigration FN topped the vote in six of 13 regions in last weekend's first round, capitalizing on the public's security fears in the wake of the jihadist attacks in which 130 people died.

Police in Geneva raised the terror alert level and were searching Geneva on Thursday for several suspected jihadists believed to have links to the Islamic State group, security sources said. 

A statement from the Canton of Geneva's security department said it had received information on Wednesday from Swiss federal authorities concerning "suspicious individuals likely to be in Geneva or the Geneva area."

Former French president Jacques Chirac is in hospital for a check-up, but his state of health is not a cause for concern, his daughter told AFP on Thursday.

Chirac, 83, who was head of state from 1995 to 2007, was taken to hospital in Paris on Wednesday and is expected to remain under observation for several days, his daughter Claude Chirac said.

French President Francois Hollande called Wednesday for unity following the record showing of the far-right National Front in regional polls, which have left traditional parties divided over how to fight back.

There needs "to be clarity in the behavior and attitude of all political leaders to defend the values of the Republic," Hollande said through his spokesman ahead of Sunday's decisive second round of voting.

French police have identified the third gunman from the deadly attack on the Bataclan concert hall in Paris, Prime Minister Manuel Valls said Wednesday, with the attacker's father telling AFP he "would have killed him" if he had known.

"The last time I saw him was two years ago before he went (to Syria)," Said Mohamed-Aggad said. "I have no words, I only found out this morning. I have to pull myself together."

An Air France flight from San Francisco to Paris was diverted to Montreal "as a precaution" after an "anonymous threat," the airline told AFP on Tuesday.

Flight AF083 from San Francisco to the main Paris airport of Charles de Gaulle touched down just before midnight local time in Montreal, the firm said.

France's far-right National Front (FN) on Monday stood at the gates of power in several regions after record scores in the first round of elections, held just three weeks after the Paris attacks.

Marine Le Pen's party finished top in six of 13 regions on Sunday, from the economically depressed north where she is standing, to the sun-drenched south where her 25-year-old niece is in poll position.

One is a pragmatist: a 47-year-old lawyer by training who has steered France's far-right National Front (FN) from pariah status to mainstream.

The other is an ideologue: her 25-year-old niece, a photogenic Roman Catholic traditionalist with a stance on abortion, homosexuality and Islam that critics say is dangerous or sectarian.

One of the perpetrators of the deadly Paris attacks visited London and Birmingham earlier this year to meet people suspected of plotting terror activity in Britain, The Guardian reported Saturday.

The newspaper, citing counter-terrorism officials, said the unnamed attacker had managed to enter Britain and travel to the nation's two biggest cities, before heading back to continental Europe undetected despite heightened security.