Pope Benedict XVI, meeting with Rome's chief rabbi Monday, expressed pain and worry over fresh outbreaks of anti-Semitism, and called on Jews and Christians to wage a united battle against hate. Waves of anti-Semitic violence and vandalism have hit Europe in the past few years. Last week, worshippers in a Moscow synagogue were attacked by a man with a knife. Benedict did not mention specific occurrences of anti-Semitism in his speech to greet Rabbi Riccardo Di Segni in an audience at the Vatican. The rabbi led a delegation from Rome's Jewish community, one of the oldest in the world.