In his Christmas message, Pope Francis urged Friday the world to unite to end atrocities by Islamist terrorists that he said were causing immense suffering in many countries, in a reference to the Islamic State group.

He read his traditional Christmas Day "Urbi et Orbi" (to the city and the world) address from the central balcony of St. Peter's Basilica as security was tight around the area.

"May the attention of the international community be unanimously directed to ending the atrocities which in those countries, as well as in Iraq, Libya, Yemen and sub-Saharan Africa, even now reap numerous victims, cause immense suffering and do not even spare the historical and cultural patrimony of entire peoples,'' he said.

The pontiff condemned recent "brutal acts of terrorism," including the Nov. 13 attacks by Islamist terrorists that killed 130 people in Paris, and the downing of a Russian plane over Egypt's Sinai peninsula that killed 224 people on Oct. 31. Both were claimed by Islamic State.

"Only God's mercy can free humanity from the many forms of evil, at times monstrous evil, which selfishness spawns in our midst," he said. "The grace of God can convert hearts and offer mankind a way out of humanly insoluble situations.".

He also called for peace between Israelis and Palestinians in the area where Jesus was born.

"Where peace is born, there is no longer room for hatred and for war. Yet precisely where the incarnate Son of God came into the world, tensions and violence persist, and peace remains a gift to be implored and built," he said.