Pope John Paul II condemned anti-Semitism Sunday in a message read in Rome's central synagogue, where the pontiff made history with a visit in 1986.
The pontiff sent two top-ranking cardinals to the ceremony marking the 100th anniversary of the temple.
Last month, a senior Vatican official said John Paul turned down the Jewish community's invitation to attend because he didn't want to take away from the "unique and historic" character of his visit two decades ago, the first ever by a pope to a synagogue.
Heavy security surrounded the gathering in the monumental temple, whose soaring dome dominates Rome's Old Ghetto neighborhood, home to one of the world's longest continuously inhabited Jewish communities.
In 1982, Arab terrorists attacked the synagogue, killing a 2-year-old boy and wounding 36 people.
Cardinal Camillo Ruini, president of the Italian bishops conference and papal vicar for Rome, read the message from the pope, who said his 1986 visit "remains engraved in my memory and my heart as a symbol" of improved relations between Jews and the Catholic church.
"The Church has restated in a clear and definitive way the refusal of anti-Semitism in all its expressions," the pontiff said. His message referred to the groundbreaking declaration of the Second Vatican Council in the 1960s.
But "the dutiful deploring and condemnation of hostilities against the Jewish people, which often characterized history, isn't enough," the message said. "We need to also develop friendship, esteem and brotherly relations" with Jews.
Only hours earlier, European Jewish leaders meeting in Hungary said anti-Semitism was on the rise.
Accompanying Ruini was Cardinal Walter Kasper, who heads the Vatican's office for relations with Jews.
Other guests included Israel's chief rabbis, the mayor of Rome, the Israeli ambassador to Italy, a top aide to Italian Premier Silvio Berlusconi and a representative of the Muslim community in Italy.
John Paul recalled the 2,091 Jews who were rounded up in the neighborhood when the city was occupied by Germany in World War II and sent to Nazi concentration camps.
About 13,000 Jews live in Rome, a city of some 2.7 million people.