Vatican City, Mar 12 (EFE).- The 115 cardinal electors who will choose Benedict XVI's successor locked themselves in the Sistine Chapel on Tuesday and began the process of picking the next pontiff from their own ranks.
The Master of the Papal Liturgical Celebrations spoke the phrase "Extra Omnes" (outside, all of you), officially starting the conclave.
The Sistine Chapel's doors were closed at 5:35 p.m. (1635 GMT) once all of the cardinals had taken their oaths of secrecy as established in the Universi Dominici Gregis Apostolic Constitution for the election of the pope.
Once the doors closed, one of the cardinals, Malta's Prosper Grech, led a meditation on the election of the pontiff.
After the meditation ended, Grech and the Master of the Papal Liturgical Celebrations, Archbishop Guido Marini, left the Sistine Chapel and the doors were once again closed.
The conclave is being guided by Cardinal Giovanni Battista Re because the dean of the College of Cardinals, Cardinal Angelo Sodano, and the vice dean, Roger Etchegaray, cannot be in the Sistine Chapel because they are both octogenarians.
Each of the 115 cardinal electors has the "Universi Dominici Gregis," the "Ordo Rituum Conclavis" and the liturgy of the hours at his place.
Hundreds of people gathered in St. Peter's Square to await the signal from the cardinals on whether a new pope had been selected.
The first round of voting will be followed by the traditional "fumata," the smoke signal issuing from the Vatican rooftop, which if white indicates a new pope has been elected, and if black, no one has yet been selected.
Cardinal Sodano celebrated Mass earlier Tuesday ahead of the start of the enclave.
Sodano called for unity in the Catholic Church and asked God to provide the faithful with another pontiff with a "generous heart" who will work tirelessly for justice and peace in the world.
The 115 cardinal electors, other members of the clergy, the diplomatic corps and thousands of the faithful attended the "pro eligendo Romano Pontifice" Mass at St. Peter's Basilica.
"St. Paul teaches us that all of us must also work together for the unity of the church and we must cooperate with the successor to St. Peter, a visible foundation of ecclesiastical unity," Cardinal Sodano said.
The next pope will need a two-thirds majority of the cardinals present. Since there are 115, he will need a minimum of 77 votes.
The College of Cardinals, called the "most exclusive club in the world," is composed of 207 cardinals from 66 countries, 51 of which have cardinal electors.
Of these cardinals, two were appointed by Paul VI, 117 by John Paul II, and 90 by Benedict XVI, who stepped down on Feb. 28.
The leading candidates, according to observers, are Italian Angelo Scola, the 71-year-old archbishop of Milan; Brazilian Pedro Odilo Scherer, the 63-year-old archbishop of Sao Paulo; Canadian Marc Ouellet, the 69-year-old president of the Pontifical Commission for Latin America' and Archbishop of Boston Sean O'Malley, a 68-year-old Capuchin.