Pope Francis has prayed for the 39 girls killed and others injured in the blaze that began in a Guatemalan youth shelter when mattresses were set alight in a protest by those living there.
Greeting the faithful in St Peter's Square on Sunday, Francis also prayed that God console the victims' families.
He added that he was praying and asked others to do likewise "for all the girls and boys who are victims of violence, maltreatment, exploitation and war" in the world.
The Pope said: "This is a plague, a hidden cry that must be listened to by all of us. We can't continue to pretend not to see and not to hear it."
The inferno on Wednesday has drawn attention to alleged failings in Guatemala's child protective services.
