‘’France without its Jews is not France,’’ said French Prime Minister Manuel Valls as he spoke Saturday evening at a ceremony commemorating the four Jewish victims of a terrorist attack by an Islamist gunman against a kosher supermarket one year ago in Paris.

He stressed that the thought of Jews leaving France because they no longer feel it is their home was “an unbearable idea.”

"For these enemies who attack their compatriots, who tear apart the contract that unites us, there can be no worthy explanation," he said, acknowledging the "immense anguish" of the Jewish community.

More French Jews emigrated to Israel last year than ever before, according to figures from the Jewish Agency — some because of security concerns after last year's attack.

Speaking outside the Hyper Cacher supermarket at Porte de Vincennes, Valls vowed to fight anti-Semitism in all its forms.

Nothing, he said, could explain an attack by a Frenchmen on fellow citizens. “Nothing can explain the killing at outdoor cafes. Nothing can explain the killing in a concert hall. Nothing can explain the killing of journalists and police. And nothing can explain the killing of the Jews! Nothing can ever explain it”.

The “unitary and republican gathering’’ to pay tribute to the victims of the attack was organized by CRIF, the umbrella representative of French Jewish institutions.

Candles were lit one by one by several officials including the chief rabbi of France, Haim Korsia, the Archbishop of Paris, André Vingt-Trois, the leader of the French Council of the Muslim Faith (CFCM), Anwar Kbibech, and former president Nicolas Sarkozy.

“The year 2015 was a horrible year for Jews, for journalists, for police and eventually for all the French,” CRIF President Roger Cukierman said.

Saturday evening's ceremony was part of a weekend of efforts to ease religious tensions and mark the anniversary of the attacks on the kosher supermarket and on the satirical newspaper Charlie Hebdo.