On the last day of his US visit Pope Francis toured the streets of Philadelphia in his open-sided white Jeep Wrangler popemobile. His choice of vehicle in Washington had been similarly modest - a Fiat 500.

The Pope greeted tens of thousands of people lining the streets on Sunday. They had come to take part in the celebrations of the Vatican-sponsored festival "The World Meeting of Families."

Pope Francis celebrated an open-air Mass on the steps of the Philadelphia Museum of Art for the people gathered on the tree-lined boulevard. Philadelphia Archbishop Charles Chaput said the crowd numbered more than a million.

"The urgent challenge of protecting our home includes the concern of bringing all of the human family together in the pursuit of sustainable and integral development," Pope Francis said.

Church officials said the next World Meeting of Families would be held in Dublin in 2018.

Sex abuse victims

Earlier Pope Francis met with three women and two men who were victims of sexual abuse. "I have in my heart the stories of suffering and the pain of the minors who were sexually abused by priests," Pope Francis said afterwards in Spanish to a meeting of bishops.

"This disgrace keeps burdening me, that the people who had the responsibility of caring for these tender ones raped them and caused them great pain. God weeps for the sexual abuse of children," he said.

The Archdiocese of Philadelphia has been the subject of a series of damaging grand jury reports relating to sexual abuse, which by the Church's own estimate has involved 6,400 clergy accused between 1950 and 2013 across the US.

Pope Francis commented: "all responsible will be held accountable."

Jail visit

Also Sunday, Pope Francis visited a Philadelphia jail, the Curran Fromhold Correctional Facility, and met with 60 men and 11 women dressed in blue prison uniforms (photo). He is an outspoken opponent of the death penalty and lengthy prison terms.

"May you make possible new opportunities, new journeys, new paths," he said, standing before a wooden chair the inmates had made for him for the occasion.

Pope Francis left Philadelphia on an American Airlines flight for Rome on Sunday night. Among the dignatories seeing him off was Vice President Joe Biden.

jm/bw (Reuters, AP)