VATICAN CITY - Pope Benedict XVI celebrated Christmas Midnight Mass early today by sending out an appeal for children who are abused, are forced to live on the street, or serve as soldiers.

In the splendor of St. Peter's Basilica, Benedict marked the birth of Jesus with a call to the faithful to help children who are denied the love of their parents and those who are exploited across the world.

"The Child of Bethlehem summons us once again to do everything in our power to put an end to the suffering of these children," he said.

Delivering his homily in Italian, Benedict recalled the plight of "street children who do not have the blessing of a family home, of those children who are brutally exploited as soldiers and made instruments of violence, instead of messengers of reconciliation and peace."

He spoke of minors who are "victims of the industry of pornography and every other appalling form of abuse, and thus are traumatized in the depths of their soul."

The pope did not mention lawsuits and other complaints in the United States and elsewhere by Catholics who allege they were sexually abused by priests when they were youngsters.

As he recalled the birth of Jesus in biblical Bethlehem, Benedict's thoughts turned to the Holy Land, and the pontiff, 81, prayed for an end to the conflict between Israel and the Palestinians.

Benedict is expected to visit the Holy Land in May for what would be the first papal trip to Israel and the Palestinian territories since Pope John Paul II traveled there in a 2000 pilgrimage.

As Midnight Mass began, Benedict, dressed in white and gold-colored vestments, walked in a procession up the basilica's main aisle, smiling and stopping several times to shake outstretched hands and bless children.

As a choir intoned a psalm, the pope sprinkled incense on the central altar under Gianlorenzo Bernini's towering bronze baldachin before opening the service with the traditional wish for peace in Latin: "Pax vobis" ("Peace be with you"). The faithful responded: "Et cum spiritu tuo" ("And also with you").

Thousands of pilgrims, Romans and tourists packed the basilica for the midnight service. For those unable to enter, giant screens were set up in St. Peter's Square.

Earlier, as night fell on Christmas Eve, Benedict appeared at his studio window to bless the crowd in chilly St. Peter's Square and light a candle in a sign of peace.

The Christmas festivities began with the unveiling of the larger-than-life Nativity scene next to the Vatican's largest-ever Christmas tree in the square.

Children in Santa hats sang holiday hymns as the Vatican's Gendarmeria band played alongside.