More than 6,000 extra police, including snipers, bomb-disposal experts and motorcycle escorts, have been deployed to protect the crowds of faithful and world leaders converging on the Vatican to mourn Pope John Paul II (search).

About 1,500 officers will be assigned to the hundreds of foreign dignitaries, including President Bush, expected to attend Friday's funeral. The Interior Ministry said it has enough armored cars to protect those who need them.

Despite the large number of uniformed police around St. Peter's Square (search) and in the tourist areas of Rome on Monday, there was no imposing presence of riot squads or police helicopters. If snipers were on rooftops, they were out of view of people in the square.

Though metal detectors are permanently installed around the square and normally used for papal functions, only a few people were scanned with hand-held detectors on Monday.

But just before John Paul's body was carried toward St. Peter's Basilica (search), police cleared mourners from a large area of the square until his remains were inside the basilica for the public viewing.

Dozens of uniformed police walked with the crowd as people filed behind a red-draped security barrier past the pontiff's remains.

Throughout the day, much of the square and the wide boulevard leading up to it were blocked off by metal barricades. Dozens of Carabinieri paramilitary police lingered beyond the fencing where people waited in line to enter the basilica.

Police quickly stopped a few people who tried to climb over the barriers. On one street, officials in orange jumpsuits linked hands in a human chain to keep people in line.

Security was stepped up last week after the pope's health began to deteriorate and pilgrims started to arrive in Rome to pray for his recovery.

John Paul II was elected in 1978, the year Italian politician Aldo Moro was kidnapped and assassinated by Red Brigades terrorists. But even then, security remained light at the Vatican.

It was only seriously stepped up after Turkish gunman Mehmet Ali Agca fired from a crowd in the virtually unguarded St. Peter's Square and wounded John Paul in 1981.

Measures were further increased sharply following the worldwide terror alert triggered by the Sept. 11, 2001 attacks in the United States. They are especially tight over the Christmas and Easter holidays, when large crowds arrive.

In addition to the Swiss Guards posted at the basilica in blue-and-yellow striped uniforms and carrying ceremonial weapons, the Vatican security detail numbers some 200 people, including the pope's bodyguards and a special corps from the Italian police.

The pope's limousine is armored, but cars used by cardinals don't appear to be.