At a ceremony Saturday evening commemorating the four victims of a jihadist attack on a kosher supermarket in Paris, French Prime Minister Manuel Valls said the thought of Jews leaving France because they no longer feel it is their home was “an unbearable idea.”

Valls, speaking outside the Hyper Cacher supermarket, said France without its Jewish community was “not France” and 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,” he called, to cheers from the crowd.

Crif's president Roger Cukierman lights candles on January 9, 2016 near the Hyper Cacher (AFP / POOL / JACQUES DEMARTHON)

Crif’s president Roger Cukierman lights candles on January 9, 2016 near the Hyper Cacher (AFP / POOL / JACQUES DEMARTHON)

The “unitary gathering of tribute” to the victims of the January 2015 attack began in the evening, after the Sabbath. It was organized by the Representative Council of Jewish Institutions in France (CRIF).

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.

Chief Rabbi of France Haim Korsia lights candles on January 9, 2016 near the Hyper Cacher (AFP / POOL / JACQUES DEMARTHON)

Chief Rabbi of France Haim Korsia lights candles on January 9, 2016 near the Hyper Cacher (AFP / POOL / JACQUES DEMARTHON)

Tributes were also paid Saturday to Clarissa Jean-Philippe, a young policewoman who was also killed by the gunman who went on to carry out the supermarket siege, with President Francois Hollande unveiling a plaque in her honor in the Paris suburb of Montrouge where she died.

A total of 17 people were killed in the January 2015 attacks which rocked France and touched off a wave of Islamist violence that reached a head in November when a group of gunmen and suicide bombers unleashed mayhem in Paris, killing 130.

The 26-year-old policewoman was killed on January 8 by Amedy Coulibaly, the gunman who went on to attack the Hyper Cacher supermarket in east Paris. Three shoppers and an employee were killed by Coulibaly before he was killed in a police raid.

French President Francois Hollande (2nd R) and mayor of Montrouge Jean-Loup Metton (R) lay a wreath of flowers honoring late policewoman Clarissa Jean-Philippe in Montrouge south of Paris, on January 9, 2016. (AFP/POOL/Michel Euler)

French President Francois Hollande (2nd R) and mayor of Montrouge Jean-Loup Metton (R) lay a wreath of flowers honoring late policewoman Clarissa Jean-Philippe in Montrouge south of Paris, on January 9, 2016. (AFP/POOL/Michel Euler)

“Despite continuing traumatic feelings, life has returned to normal with a renewed sense of fraternity,” said chief rabbi Korsia.

Commemorations will culminate in a public event on Sunday in the Place de la Republique, the vast square that became the rallying point for “Je Suis Charlie” solidarity movement, and for similar movements after the deadly November 13 attacks.

The four victims of the Paris Hyper Cacher attack, from left to right: Yoav Hattab, Yohan Cohen, Francois-Michel Saada, Philippe Braham. (photo credit: Courtesy)

The four victims of the Paris Hyper Cacher attack, from left to right: Yoav Hattab, Yohan Cohen, Francois-Michel Saada, Philippe Braham. (photo credit: Courtesy)

There, a 10-meter (35-foot) oak will be planted as a “tree of remembrance.” Veteran French rocker Johnny Hallyday was to perform “Un Dimanche de Janvier” (One January Sunday), a song recalling the vast mobilization that saw 1.6 million people march in Paris on January 11, 2015.

Also this weekend, mosques around the country are opening their doors to visitors in a move to “highlight the real values of Islam, to set straight the cliches about links to violence and terrorism,” Anouar Kbibech, head of the French Council of the Muslim Faith, told AFP.