A statue of the Virgin of Fatima, who the Pope believed saved his life, was flown in from Portugal for a special Mass at St Peter's Basilica.

John Paul was critically wounded when he was shot three times by Turkish gunman Mehmet Ali Agca on 13 May 1981.

A simple marble slab now marks the spot of the shooting in St Peter's Square.

Bejewelled crown

The Pope was greeting pilgrims in the square at an open air general audience when he was shot.

He recovered after emergency surgery and continued as Pope until his death last year.

On the first anniversary of the assassination attempt he visited the shrine of the Virgin of Fatima in Portugal to give thanks for his recovery from his severe injuries.

He firmly believed his life had been saved by the Virgin and gave one of the bullets extracted by surgeons to be incorporated in a bejewelled crown placed on the head of her statue.

This statue - venerated by millions of pilgrims at the Portuguese shrine - was flown to Rome for the anniversary Mass, celebrated by his successor Pope Benedict XVI.

It was carried in procession past the place where the Pope was shot.

A new marble slab among the cobblestones now marks the spot.

The BBC's David Willey in Rome says it has never been fully explained whether Mehmet Ali Agca fired at the Pope on his own initiative or was commissioned.

A trial in Rome of alleged Bulgarian accomplices ended inconclusively.

But an Italian parliamentary commission announced recently it had established beyond all doubt that the former Soviet Union was involved acting through the Bulgarian secret services.

The Russian government dismissed the findings.