St. Peter's Square fills up for Pope Francis installation

VATICAN CITY (AP) - Thousands of people are pouring into St. Peter's Square to witness the official start of the papacy of the first pope from the New World.

The blue and white flags from Pope Francis' native Argentina fluttered on Tuesday above the crowd that Italian media estimate could reach 1 million.

Emergency crews set up barricades for nearly 2km along the main boulevard leading to the square to control the masses.

The installation Mass is simpler than the 2005 ceremony for Pope Benedict XVI in keeping with Pope Francis' style, but still grand enough to draw 132 official delegations and religious leaders from around the world.