VATICAN CITY (AP) _ There was a moment of panic Sunday in St. Peter's Square at the start of the Rome marathon when people apparently thought the starting pistol was real gunfire.

Pope John Paul II had just blessed the runners in the Vatican's inner courtyard and was walking in the square to begin an outdoor Mass when the starting pistol was fired for the race.

Witnesses said people in the square near the shot appeared shocked. Some screamed, others began running, but calm was quickly restored, they said.

About 30,000 people took part in the service during which John Paul beatified four people, a step toward possible sainthood.

It was in the same square where John Paul was wounded May 13, 1981, by Turkish terrorist Mehmet Ali Agca, now serving a life term for the shooting.

The marathon was sponosored by Catholic organizations.