Israel expects the number of French Jews moving there this year, which was already predicted to rise sharply from 2014′s record level, to accelerate further after the killings at a Paris kosher grocery, a senior official said on Sunday.

Natan Sharansky, head of the Jewish Agency promoting emigration to Israel, said his estimate for 2015 was 10,000 French immigrants, after 3,300 in 2013 and 7,000 last year.

"It will probably be much more than 10,000," he told Reuters at a Jewish Agency meeting for French considering emigration. Israeli Foreign Minister Avigdor Liebermann, at his side, said about 700 Jews had attended the session during the day.

Both men flew to Paris with Prime Minister Benjamin Netanyahu for a mass protest on Sunday that united world leaders – including Muslim and Jewish statesmen – with over a million French to honour 17 victims of Islamist militant attacks.

They later attended a memorial service for all the victims at the Paris Grand Synagogue with Hollande and Prime Minister Manuel Valls.

The victims died in three days of violence that began with an attack on the satirical newspaper Charlie Hebdo on Wednesday and ended with a hostage-taking at a kosher supermarket on Friday. Four were killed at the Jewish shop.

Roger Cukierman, head of the CRIF umbrella group of French Jewish organisations, said after meeting President Francois Hollande that he was promised army protection if needed for Jewish institutions in France.

"They told us that all schools and all synagogues will be protected in measures that, if necessary, extend beyond the police to the army," he said.

The attacker who took hostages at the kosher supermarket said he was targeting the Jewish community. The gunman, Amedy Coulibaly, was killed as police broke the siege.

The two gunmen who attacked the weekly Charlie Hebdo, killing its editor-in-chief and leading cartoonists, were also killed in another shootout north of the capital. Police said all three belonged to the same Paris-based Islamist militant cell.

France has the largest Jewish population in Europe, having grown by nearly half since World War Two to total some 550,000 according to CRIF. Anti-Semitic threats and incidents more than doubled last year, according to the Ministry of the Interior.

Israeli officials, including Netanyahu, have long encouraged French Jewish emigration.

In a statement late on Saturday, Netanyahu said an Israeli governmental committee would convene in the coming week to find ways to boost Jewish immigration from France and other European countries "which are being hit by terrible anti-Semitism".