MOSCOW, July 13 (JTA) — The business manager of Moscow’s Jewish Arts Center was hospitalized in serious condition after he was attacked by a young man wielding a knife. Leopold Kaimovsky, 52, was wounded in the face, stomach and leg Tuesday after a religious service in the Choral Synagogue, which houses the art center’s offices. Security officials at the synagogue subdued the attacker until police arrested him. As he was taken away, the assailant shouted, “There are 50,000 of us. We will kill all of you anyway,” according to Pavel Feldblum, the executive vice president of the Moscow Jewish Community, whose office is also located in the synagogue. The man, identified by police by his last name, Krivchun, is a 20-year-old student at a Moscow university who has confessed to a plan to set the synagogue on fire, according to police investigators. A longtime Jewish activist, Kaimovsky is a well-known member of the Jewish community here. Immediately after the attack, police could not confirm whether the assailant was a member of any neo-Nazi group, but the 50,000 number that the assailant mentioned is the most frequently cited estimate of members of Russian National Unity, Russia’s largest and best-organized neo-Nazi group. The attack is sending shock waves throughout Moscow’s Jewish community. In the afternoon, Jews from across the Russian capital flocked to the synagogue, which is located in the center of the city just a few blocks away from the Kremlin. “I came to find out if any help is needed,” said a young man who gave his name as Boris. “I could never think this can happen in Moscow,” he added, as he looked at the main staircase spilled with blood. Russia’s chief rabbi accused authorities for what many here see as a failure to crack down on prominent hard-liners who have made inflammatory statements in the past year. “This is a result of the absolute impunity of the people who are making anti-Semitic statements,” said Rabbi Adolf Shayevich, referring to Communist lawmaker Albert Makashov and Russian National Unity leader Alexander Barkashov. Russian and Moscow authorities have not yet commented on the incident.