MOSCOW — A rabbi's 12-year-old son prevented a bomb from exploding inside a Moscow synagogue Sunday.

The incident at the Bolshaya Bronnaya shul came less than two weeks after a Moscow Jewish leader was stabbed inside another synagogue in the Russian capital.

Then, on Tuesday, police evacuated Bolshaya Bronnaya after an anonymous caller phoned in a bomb threat. No explosives were found.

No one was hurt in Sunday's incident but it is likely to exacerbate already-simmering anger within the Jewish community as promises for heightened security at Jewish sites continue to go unmet.

Josef Kogan, the son of Lubavitch Rabbi Itzhak Kogan, discovered the bomb in the synagogue's main hall a few minutes before a ceremony for a young boy's first haircut was set to begin. The synagogue was packed with a large number of small children, and was decorated with balloons.

A bomb squad detonated the explosive nearby. The explosion shattered window panes at the shul and in neighboring buildings.

"It's a miracle that no one was hurt," Itzhak Kogan told the JTA minutes after the bomb was detonated.

Dozens of Jews who were evacuated from the Lubavitch synagogue burst into applause when they heard the powerful explosion.

According to a Federal Security Service agent who did not give his name, the bomb contained an equivalent of more than a pound of TNT.

"It could have gone off when we were inside," said a young woman who was in the shul when the bomb was found. "I still can't believe it. We could have been killed," she said, her lips trembling.

Monday, Moscow Mayor Yuri Luzhkov called Sunday's incident and the stabbing "anti-Semitic acts of terror."

He added that the two incidents were directed against all Muscovites, not only its Jewish citizens.

In the wake of the July 13 stabbing of Leopold Kaimovsky at the Choral Synagogue, Russian authorities vowed to tighten security measures at all Moscow synagogues that are currently guarded by private security agencies.

Those promises have yet to be fulfilled.

Jewish officials say they are not surprised because a similar failure to follow up on security promises occurred after bomb blasts near two Moscow synagogues in May.

In the meantime, Jewish communal leaders are busy upgrading security measures themselves at Jewish sites in Russia.

The changes are evident at the Choral Synagogue, where visitors are now required to pass though an airport-style security system.

Jewish officials say they are preparing to introduce similar measures, which have become commonplace in many Moscow restaurants and office buildings, at most Jewish sites in Moscow and elsewhere in Russia.

Currently, only two Moscow synagogues have adequate security systems, while schools, offices of Jewish organizations and soup kitchens lack even the basic measures.

Increased security, of course, translates into increased costs, and with that in mind, the Moscow community established this week a special foundation to raise funds in Russia and abroad to provide communal institutions with updated security.

Information about the Security Foundation of the Russian Jewish Community can be obtained in English on the Web at www.chat.ru/~jsfund

"We are witnessing a surge of anti-Semitism. This does not mean that people don't see a future here anymore. What we have to do now is to struggle for this future, to learn to protect ourselves," said Pavel Feldblum, the executive vice president of the newly created Moscow Jewish Community.

The organization, created recently by 40 prominent Jews, is seeking to unite the Jewish organizations that operate in Moscow.

The board includes prominent businessmen, lawyers, Russia's former foreign minister, the coach of the national basketball team and a top-ranked police official.

One of the country's best-known entertainers has become president.

Comedian Gennady Khazanov, known as "Russia's Bob Hope," said he understood only recently the importance of being personally involved in the Jewish community.

"You can give concerts here or abroad yet there is a more meaningful way you can try to make a difference with your life" said Khazanov, who is 55.

Last week, after the synagogue stabbing, Khazanov made several television appearances as president of the organization.

Sporting a white silk kippah — something he had rarely done before — the comedian focused public attention on the incident.

Khazanov isn't the only public figure who has been prompted by the stabbing incident to come out of the Jewish closet.

Former foreign minister Andrei Kozyrev, who is partly Jewish, said the current surge of anti-Semitism has prompted him to join the recently created group.

As its first goal, the Moscow Jewish Community plans to raise and distribute $800,000 for existing communal projects in the capital.

Meanwhile, reports in the mainstream Russian press this week are accelerating concerns about an even larger surge in anti-Semitism.

Several newspapers criticized former Russian Prime Minister Viktor Chernomyrdin for saying that a battle between two of Russia's leading business tycoons was a struggle between "two Jews."

Commenting on an unprecedented media war between the ORT channel, controlled by Boris Berezovsky, and NTV, owned by Vladimir Goussinsky, Chernomyrdin told a news conference in Moscow, "It comes out that two Jews have clashed, and now the whole country has to watch this farce."

Many Jewish officials and ordinary Jews said they were shocked by the comment from Chernomyrdin, who had not previously made anti-Semitic remarks in public.

In a front-page article, Russia's leading business daily Kommersant wrote that the remark was an indication of a looming "anti-Semitic epidemic" in advance of this December's parliamentary election.