Pope Francis invoked the ‘’unbreakable bond’’ between Jews and Christians as he visited the Great Synagogue of Rome on Sunday.

He also rejected all forms of anti-Semitism and called for "maximum vigilance" and early intervention to prevent another Holocaust.

It was his first visit to a synagogue as pontiff. The pope was greeted with applause as he arrived Under tight security and was met on the synagogue steps by Rome's chief rabbi Riccardo Di Segni.

Located just across the River Tiber from the Vatican, it stands in an area still known as the Ghetto where under the orders of some of Francis's predecessors, Jews were confined for more than three centuries until their emancipation at the end of the 19th Century.

Francis began his visit by laying a wreath at a plaque outside the synagogue marking where Roman Jews were rounded up by the Nazis in 1943 and at another marking the slaying of a 2-year-old boy in an attack by Palestinians on the synagogue in 1982.

He met with members of the boy's family and survivors of the attack before entering the synagogue to rounds of warm applause, which continued during his speech, interrupting him several times.

The Argentine Jesuit has a longstanding friendship with the Jewish community in Argentina from his time as archbishop of Buenos Aires.

Pope Francis is the third pope to visit Rome's main synagogue in a sign of continued Catholic-Jewish friendship that was highlighted by a recent Vatican declaration that it doesn't support official efforts to convert the Jews.

Amost 30 years ago, John Paul II became the first pontiff to visit a synagogue and six years ago Pope Benedict XVI also visited.

But Pope Frncis's visit also follows a series of developments that have upset some in the Jewish community, including a new Vatican treaty signed with the "state of Palestine" and Francis' own words and deeds that have been interpreted by some as favoring the Palestinian political cause.

In an interview on Friday, Rabbi Di Segni said that the pope’s visit was aimed at showing five decades of improving Christian-Jewish relations and interfaith harmony, at a time of Islamic extremist violence around the globe.

But he said some recent Vatican developments "cannot be so appreciated by the Jewish community."