A day after mounting a scare-tactic campaign to prevent the assimilation of Diaspora Jews, the Prime Minister's Office and Jewish Agency received some 200 calls, most of them reporting names of Jews living abroad.

However, many callers also blasted the campaign - which describes assimilation as a "strategic national threat."

The campaign, which launched on Wednesday, urges Israelis to report the particulars of acquaintances living abroad so that these people, who are "in danger" of marrying non-Jews, can be persuaded to come to Israel.

The 10-day Hebrew-language campaign has been mounted by MASA, a partnership between the Jewish Agency and the Israeli government that helps finance and market Israel programs for Diaspora Jews.

It features images of missing-person posters, with Jewish-sounding names written along the bottom. The message is that assimilated Jews are "lost" persons who must be brought home, to Israel.

Campaign organizers say that about half the world's Jews marry outside the faith, and are calling on Israelis and Jews to enlist to prevent the "strategic national threat" posed by assimilation.

About 100 of the callers reported unmarried Jews aged 18-30 living in France, the United States and New Zealand. Callers also left their acquaintances' Facebook and Twitter names as well as email addresses so that MASA people could contact them.

The campaign also evoked many angry phone calls, some calling the campaign a "farce."

"Are we also supposed to report acquaintances who don't intend to have children?" one caller asked.

"We wanted to raise a public debate, even if it arouses argument and emotions," MASA's CEO Ayelet Shiloh-Tamir said Thursday.

"More than 50 percent of young Jews assimilate," the TV commercial informs viewers through the voice of Ayala Hasson, a top reporter for Channel 1. "We are losing them," she adds, as soft, melancholy music is played on a flute in the background.

The 33-second clip features images of missing-person posters hanging in locales in Europe and North America. The posters, in English, French and Russian, are of young people with Jewish-sounding names.

The ad then asks anyone who "knows a young Jew living abroad" to call MASA. "Together, we will strengthen his or her bond to Israel, so that we don't lose them," the announcer concludes.

MASA officials say that Jewish youngsters who participate in the organization's projects strengthen their Jewish identity and affinity to Israel.