TEL AVIV—Miriam and Emmanuel Riva were “the cream of the crop,” grieving family and friends said of the 50-year-old couple, slain in May 24’s shooting attack at the Jewish Museum in Brussels, Belgium.

Two employees of the center were also killed, Israel Radio said.

The couple, who lived in Tel Aviv and leave behind a 15- and a 17-year-old daughter, were Israeli Foreign Ministry employees for the last four years, and were due to return to Israel on May 29, friends said.

“Up until two years ago, Emmanuel was the vice-consul in Berlin; they were cultured people of character who loved Israel,” said Josia Porat, Emmanuel’s cousin’s wife.

As horrified family members in Israel and the United States were notified, relatives and school officials prepared to look after the daughters, Porat told Israeli daily Ma’ariv.

For the moment, “the family has decided not to tell Emmanuel’s father, who is over 90 years old, of the murders,” the Belgian–born Porat said.

“The anti-Semitism there is shocking,” she said. “It’s not what it once was.”

Meanwhile, in Brussels, local police and officials speculated that “everything is possible,” as to the attacker’s motives.

“We know that the location, the Jewish Museum in Brussels, makes one think of it being an anti-Semitic attack, but we do not have enough to confirm this is the case,” a state Prosecutor’s Office spokesman said.

Police have launched a manhunt for the gunman, and, earlier, released an individual initially detained immediately after the shootings, according to Israel’s Walla news site.

“The entire Jewish community is in shock,” in the wake of the killings, said one Jewish community leader. Another told Israel Army Radio that Belgium’s 45,000 Jews “were in a state of panic.”

“We have decided to implement deterrent measures, said Belgian Interior Minister Joelle Milquet, including beefing up the police presence in areas of Jewish concentration.

“This is the first anti-Jewish attack in Brussels since World War II,” said Dr. Maurice Sosnowski, the head of the Jewish community of Belgium.

“The Jewish community is in good standing with everyone, even the Muslim community,” another Jewish official told Israeli daily Yediot Ahronot.

Senior Israeli officials were in contact with Belgian counterparts, and President Shimon Peres called on European governments to combat anti-Semitism.

“This act of murder is the result of constant incitement against Jews and their state,” Israeli Prime Minister Benjamin Netanyahu said in a statement sent to reporters.

“I urge all the leaders of Europe—do not take anti-Semitic incidents lightly,” Peres said in a statement.

“Each incident calls for a powerful response. European leaders must wage war against anti-Semitism, as it rears its head in many European countries,” Peres said.

In related news, two unknown assailants badly hurt two Jews in Paris on Saturday night, May 24, as they left a synagogue. French police are looking for the culprits in the attack, which took place several hours after the Brussels killings.

It is unclear at this stage if there was a direct connection between the two attacks.