After a prayer service attended by cardinals, prelates and dignitaries, the doors of St. Peter's swung open, and police intervened to control the crush when the public was allowed to enter, an Italian news agency said. There was no immediate report of serious disorder or injury.
People crossed themselves as they filed past. Some took pictures of John Paul in his crimson robe and white bishop's miter.
Earlier, applause rose from the tens of thousands of mourners in St. Peter's Square as 12 pallbearers, flanked by Swiss Guards in red-plumed helmets, carried the body on a crimson platform through the Bronze Door into the piazza.
Many more pilgrims were converging on Rome for the funeral, set for Friday by the College of Cardinals, which held two meetings in its first gatherings ahead of a secret vote later this month to elect a successor to John Paul.
The funeral is expected to draw up to 2 million people, including heads of state such as President Bush and his wife, Syrian President Bashar Assad, and Prince Charles, who delayed his wedding a day to attend.
The procession, to the backdrop of priests chanting the Litany of the Saints, began at the Sala Clementina in the Apostolic Palace, where John Paul had lain in state since Sunday. Televised by Vatican TV, it moved slowly through the frescoed halls, giving the general public a rare view of the inner sanctums of the Vatican.
Pope's Body Heads Toward Public Viewing
The body of Pope John Paul II began its journey from the Apostolic Palace to St. Peter's Basilica for public viewing Monday, four days before being entombed in the grotto where pontiffs throughout the ages have been laid to rest.
Tens of thousands of mourners broke into applause as 12 pallbearers, flanked by Swiss Guards, carried the body into the square on a crimson platform from the Sala Clementina, where it had lain in state since Sunday.
Before the procession began, Cardinal Eduardo Martinez Somalo said prayers and sprinkled the body with holy water as chanting echoed off the walls of the ornate Vatican hall.
Images of the procession were shown on giant screens in the square and on the main avenue toward the basilica, where more than 100,000 pilgrims, mourners and tourists solemnly watched.
Members of the College of Cardinals, the red-capped princes of the church, accompanied the procession, as well as bishops and other prelates.
They went slowly through the frescoed halls as the choir chanted, moving along the Scala Nobile, the First Loggia, the Sala Ducale, the Sala Regia and the Scala Regia.
Pope John Paul II's Funeral Set for Friday
Pope John Paul II's funeral will be held Friday morning, and his remains will be interred in the grotto of St. Peter's Basilica where pontiffs throughout the ages have been laid to rest, the Vatican said Monday.
Chief spokesman Joaquin Navarro-Valls made the announcement after the College of Cardinals held two meetings over the course of 2 1/2 hours in its first gatherings since the pope's death and ahead of a secret vote later this month to elect a successor to John Paul.
Navarro-Valls said John Paul would "almost surely" be buried in the tomb where Pope John XXIII lay before he was brought up onto the main floor of the Basilica.
That pope, who died in 1963, was moved after his 2000 beatification because so many pilgrims wanted to visit his tomb, and the grotto is in a cramped underground space.
In the first meeting, the cardinals took an oath of secrecy. In the second one, they made their decisions on the funeral rites, Navarro-Valls said. There were 65 cardinals attending.
John Paul will be buried immediately after the funeral, he said.
Archbishop Josef Clemens, secretary of the Vatican office for lay people and a former aide to top Vatican cardinal Joseph Ratzinger, said not all the cardinal electors had arrived in Rome in time to attend Monday's first session.
Poles have hoped that the pope's heart may be placed in Wavel Cathedral in Krakow, where Polish saints and royalty are buried. Asked if this was ruled out by burial in St. Peter's, Navarro-Valls did not directly reply, saying he was merely transmitting information on decisions taken by the cardinals Monday morning.
Under Vatican tradition, Friday is the latest the funeral could have been held. Up to 2 million pilgrims are expected to converge on Rome for the 10 a.m. (4 a.m. EDT) service.
Vatican Says Pope John Paul II Dies at 84
The crowd, which appeared to grow quickly, recited the rosary. A person in the front held a Polish flag in honor of the Polish-born pontiff.
"The angels welcome you," Vatican TV said after papal spokesman Joaquin Navarro-Valls announced the death of the pope, who had for years suffered from Parkinson's disease and came down with fever and infections in recent weeks.
A Mass was scheduled for St. Peter's Square for 10:30 a.m. (4:30 a.m. EDT) Sunday.
Navarro-Valls announced the death in an e-mail to journalists. "The Holy Father died this evening at 9:37 p.m. (2:37 p.m. EST) in his private apartment. All the procedures outlined in the apostolic Constitution `Universi Dominici Gregis' that was written by John Paul II on Feb. 22, 1996, have been put in motion," Navarro-Valls said.
John Paul declined rapidly after suffering heart and kidney failure following two hospitalizations in as many months. Just two hours before announcing his death, the Vatican had said he was in "very serious" condition, although he was responding to aides.
Since his surprise election in 1978, John Paul traveled the world, inspiring a revolt against communism in his native Poland and across the Soviet bloc, but also preaching against consumerism, contraception and abortion.
John Paul was a robust 58 when the cardinals stunned the world and elected the cardinal from Krakow, the first non-Italian pope in 455 years.
In his later years, however, John Paul was the picture of frailty. Although he kept up his travels, he was no longer able to kiss the ground.
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