Francis prays that the church watch over the mysteries of human salvation.
[Updated at 4:57 a.m. ET]
The Mass is moving along faster than originally planned.
[Updated at 4:55 a.m. ET]
From CNN's Kay Jones near the Vatican: Outside the square as Mass begins.
[Updated at 4:49 a.m. ET]
Pope Francis has received the fisherman's ring, a key symbol of the papacy.
[Updated at 4:46 a.m. ET]
The pallium is a cloth made of sheep's and lamb's wool, which the pope wears on his shoulders. It symbolizes him carrying the flock of believers on his shoulders.
[Updated at 4:43 a.m. ET]
Cardinal Jean-Louis Tauran presents Pope Francis with the pallium.
[Updated at 4:41 a.m. ET]
Pope Francis uses incense to indicate prayers lifting to God.
[Updated at 4:40 a.m. ET]
The vehicle the pope rode in was a Mercedes Benz G-Class sport utility vehicle.
[Updated at 4:38 a.m. ET]
Pope Francis is wearing black shoes, not red ones.
[Updated at 4:34 a.m. ET]
Pope Francis -- with cardinals and bearer the fisherman's ring and the pallium -- heads back out toward St. Peter's Square.
[Updated at 4:31 a.m. ET]
The procession heads back toward St. Peter's Square.
[Updated at 4:29 a.m. ET]
The fisherman's ring and the pallium have been removed from St. Peter's tomb.
[Updated at 4:28 a.m. ET]
Pope Francis has descended to the tomb of St. Peter in the Vatican.