PARIS (JTA) — The slaying of four Jews at a Paris kosher market may cause a substantial increase in the number of Jews who will immigrate to Israel this year, Jewish Agency Chairman Natan Sharansky said.

Sharansky arrived in Paris Sunday aboard the plane that brought Israeli Prime Minister Benjamin Netanyahu and Foreign Minister Avigdor Lieberman to France to attend a mass rally and march through Paris’ center in protest of the killing of 17 people last week by Islamists in and around the French capital.

“Before the attack, our estimates spoke of 10,000 new olim in 2015,” said Sharansky, using the Hebrew word for Jews who immigrate to Israel, or make aliyah. “In two weeks’ time we will reexamine this estimate in light of the current developments,” he told JTA at an event promoting aliyah among 55-year-olds and older in central Paris.

The event was scheduled months ago and organizers decided to go ahead with it despite the scheduling last week of the mass march following the killings at the offices of Charlie Hebdo on Jan. 7 and the murder of four Jews two days later at the Hyper Cacher kosher supermarket outside Paris.

Four hours after the event’s opening, some 500 people showed up to inquire about the possibility of making aliyah, according to Daniel Benhaim, who is the Jewish Agency’s chief envoy to Paris.

“The fact that hundreds showed up here despite the march and the transport problems it creates in central Paris is indicative of how central the concept of aliyah has become for French Jews in recent years,” he told JTA.

“We are no longer at home here,” said Yves Lellouche, a member of the Union of Kosher Consumers of France. “Fifteen of my relatives are attending a Jewish school near the site of the kosher store that was attacked. I fear for their safety. I fear for my safety.”

He said he would attend the march “but only out of curiosity, not as a militant because this is no longer my country. It was a temporary home.”

Others attendees, including Serge Luz, said they intended to march as a political act, after the aliyah event. “I see no future for myself here, but I am still French and I am still attached to the values this march is meant to defend,” he said.

Also on Sunday, Rabbi Menachem Margolin, director of the European Jewish Association, which advocates for Jewish communities in Europe, criticized calls by Jewish leaders such as Sharansky, for Jews in Paris and throughout Europe to make aliyah.

“I regret that after every anti-Semitic attack in Europe, the Israeli government dispenses the same statements about the importance of aliyah – rather than take all measures diplomats and intelligence at its disposal, in order to increase the safety of Jewish life in Europe,” Margolin told the Hebrew-language news website NRG.

“The Israeli government must stop This Pavlovian response every time there is an attack against Jews in Europe,” Margolin reportedly said.

“Every such Israeli campaign severely weakens and damages the Jewish communities that have the right to live securely wherever they are,” the rabbi said.