MANILA, Philippines — Tens of thousands of people have poured into Manila's streets to catch a glimpse of Pope Francis as he starts his first full day in Asia's largest Catholic nation under the most intense security of his pontificate.

Cell phone reception was jammed, a huge police presence guarded him and streets leading to Francis' motorcade routes were blocked as the pope set out for his official welcome ceremony at the presidential palace.

Francis leaned out the window of the simple four-door sedan to wave to the wildly cheering crowd.

Francis has a busy first day in the Philippines: He'll deliver a speech to President Benigno Aquino III and other Filipino authorities that is expected to focus on social injustice. He'll celebrate Mass in the Immaculate Conception cathedral, and finally have his first encounter with ordinary Filipinos in the afternoon.