Pope Leo has told more than a million Catholic youths at a closing Mass for a week-long encounter with the next generation of faithful that they are “the sign that a different world is possible”, where conflicts can be resolved with dialogue, not weapons.

Young people from more than 146 countries, some wearing colourful bandanas to ward off the hot summer sun, were pressed against fences in the Tor Vergata field as Leo toured the crowd in his white popemobile in late afternoon.

For the past week, these bands of young Catholics from around the world have poured into Rome for their special Jubilee celebration.