Vatican City - Pope Benedict led the world's 1.1 billion Roman Catholics into Christmas at a midnight mass Thursday in which he appealed for an end to child abuse in all its forms.
He also called for peace in the Middle East, ahead of a possible trip to the region next year.
Benedict, celebrating the fourth Christmas of his pontificate, spoke out against the abuse of minors -- ranging from parents who abandon their children to armed groups that recruit child soldiers.
"Let us think of those street children who do not have the blessing of a family home," he said during the solemn mass at St. Peter's Basilica.
"Let us think of those children who are victims of the industry of pornography and every other appalling form of abuse, and thus are traumatized to the depths of their soul."
Benedict said Catholics had to "do everything in our power to put an end to the suffering of these children."
In the past year the Pope has repeatedly addressed the issue of sexual abuse of minors by Catholic clergy, but did not raise it in his Christmas homily.
Benedict apologized for sexual abuse of minors by clergy and met victims during a July trip to Australia. He also met victims in the United States in April.
Humanity needed a "conversion of hearts" to rid the world of evil, said the Pope.
"Only if people change will the world change and in order to change, people need the light that comes from God," he said.
MIDDLE EAST PEACE CALL
Benedict called for an end to "hatred and violence" in the Middle East, which he is expected to visit in 2009.
No official announcement has been made yet but the trip is widely expected to include stops in Israel, the Palestinian territories and Jordan. It would be the pontiff's first visit to the region since his election in 2005.
"Let us think also of the place named Bethlehem, of the land in which Jesus lived and which he loved so deeply. And let us pray that peace will be established there, that hatred and violence will cease," said the Pope.
"Let us pray for mutual understanding, that hearts will be opened so borders will be opened."
The Vatican supports Israel's right to exist within secure borders alongside an independent Palestinian state and hopes a papal trip can help international efforts to bring about a comprehensive Middle East peace deal.
Later Thursday, the Pope will deliver his traditional Christmas "Urbi et Orbi" ("to the city and the world") blessing. He is also due to deliver Christmas greetings in more than 60 languages.