A fire, probably of criminal origin,  broke out briefly Sunday night at a mosque under construction in central France, officials said, the latest  in a series of attacks on Muslim targets.

The fire Sunday at the mosque in Poitiers was extinguished before fire fighters arrived, and according to local officials appeared to be the work of arsonists. 

Some 1,400 people living in France have either joined the jihadist cause in Syria and Iraq or are planning to do so, Prime Minister Manuel Valls said Monday.

"There are 1,400 individuals who are involved in the departures for jihad, for terrorism, in Syria and in Iraq," Valls told BFMTV.

Israel's Prime Minister Benjamin Netanyahu visited on Monday the kosher supermarket in eastern Paris where four Jews were killed by an Islamist gunman last week.

To the cries of "Bibi, Bibi" -- his nickname -- and under massive security protection, Netanyahu paid tribute to victims at the site, where Amedy Coulibaly took innocent shoppers hostage and murdered four.

France announced an unprecedented deployment of thousands of troops and police to bolster security at "sensitive" sites including Jewish schools Monday, the day after marches that drew nearly four million people across the country.

"We have decided ... to mobilize 10,000 men to protect sensitive sites in the whole country from tomorrow (Tuesday) evening," Defense Minister Jean-Yves Le Drian said after an emergency security meeting.

U.S. Secretary of State John Kerry said Monday he hopes to accelerate the progress of complex nuclear negotiations when he meets his Iranian counterpart later this week.

Kerry told reporters he will hold talks with Iranian Foreign Minister Mohammad Javad Zarif in Geneva on Wednesday, hoping to "accelerate the process to make greater progress."

Hollywood's A-listers hit the Golden Globes red carpet Sunday in plenty of bling and sequins, but several stars took a more sober approach, showing solidarity with France after three days of terror.

George and Amal Clooney, Helen Mirren, Kathy Bates and Diane Kruger were among those who brandished signs or wore pins reading "Je Suis Charlie" -- the rallying slogan in the wake of the deadly gun attack on French satirical weekly Charlie Hebdo.

France turns its attention Monday to plugging security holes blamed for failing to prevent the deadliest terrorist attack on the country in half a century, after millions united in historic rallies.

In the biggest show of solidarity, in Paris, more than a million people mourned the victims of three days of terror that began with a massacre at the offices of satirical magazine Charlie Hebdo on Wednesday, and ended with 17 people dead.

The two brothers who killed 12 people at French satirical weekly Charlie Hebdo had no links with Algeria, Foreign Minister Ramtane Lamamra said Sunday.

"They were never interested in obtaining Algerian papers, even if their father had at one time," Lamamra, told French radio station RFI.

Turkish Prime Minister Ahmet Davutoglu on Saturday hailed the unprecedented rally against terror in Paris as a strong message to the world, adding he would expect a similar reaction to attacks on Muslims and Islamophobia.

Davutoglu joined dozens of other world leaders at the march in Paris to mourn the victims of the three days of terror by Islamists that began with the slaughter of 12 people at the offices of satirical magazine Charlie Hebdo.

Israeli Prime Minister Benjamin Netanyahu said Sunday he appreciated the "very firm position" taken by French leaders against "the new anti-Semitism and terrorism" in France.

He also thanked Lassana Bathily, the Muslim employee of a Jewish supermarket who saved several hostages during a jihadist attack on Friday.