ROME, April 24 (Xinhuanet) -- Pope Benedict XVI was formally installed in a high-profile ceremony in the St. Peter's Square in the Vatican Sunday to officially start the ministry of the 265th leader of the Roman Catholic Church.

Pope Benedict XVI sits with cardinals during his inaugural mass in St. Peter's Square in the Vatican April 24. (Reuters)

    The open-air ceremony, known as Ceremony of Investiture, included an inaugural Mass to provide the new pope a major platform to set the tone for his pontificate.

    Attending the ceremony were an estimated 350,000 people, including a large number of pilgrims from the new pope's native Germany, political leaders and ceremonial dignitaries.

    The 78-year-old Benedict XVI was elected the 265th pope on April 19, 11 days after the death of Pope John Paul II on April 8.

    The new pope began the ceremony by processing into the area under St. Peter's Basilica where St. Peter is believed to be buried.

    In a symbolic moment of the inaugural Mass, Benedict was given a Fisherman's Ring and a woolen pallium or shawl -- symbols of the papal authority.

    Benedict ended the inaugural Mass by riding in a white open-topped white jeep surrounded by plain-clothed guards. Enditem