The pontiff urged "comfort to those who are persecuted for their religious faith, especially missionaries and members of the faithful who have been kidnapped, and to the victims of attacks by extremist groups, particularly in Burkina Faso, Mali, Niger and Nigeria".
The pope prayed for those "who suffer because of violence, natural disasters or outbreaks of disease" as well as migrants undertaking a perilous and potentially deadly sea crossing to Europe to seek a better life.
"It is injustice that makes them cross deserts and seas that become cemeteries," he said in his "Urbi et Orbi" (To the City and the World) message at the Vatican.
"It is injustice that forces them to ensure unspeakable forms of abuse, enslavement of every kind and torture in inhumane detention camps. It is injustice that turns them away from places where they might have hope for a dignified life, but instead find themselves before walls of indifference."
Pope Francis also focused on the eastern part of the Democratic Republic of Congo, plagued by insecurity for a quarter of a century due to the presence of dozens of local and foreign armed groups.
"May (Jesus Christ) bring peace to those living in the eastern part of the Democratic Republic of the Congo, torn by continuing conflicts," the 83-year-old pontiff said.