Pope Benedict XVI called for the respect of all people without discrimination and the protection of children from war and violence during a Mass on Friday marking the start of the new year.

The pontiff, also marking the Roman Catholic Church's World Day of Peace, said peace begins by recognizing that men are brothers, not rivals or enemies.

"Peace begins with a look of respect that recognizes in another man's face a person, regardless of the color of his skin, nationality, language or religion," he said during the Mass in St. Peter's Basilica.

The value of respect for all should be taught from an early age, Benedict said. Noting that classes containing children of different backgrounds are common, he said that "their faces are a prophecy of the kind of humanity we are called upon to create: a family of families and peoples."

The 82-year-old pope put children, especially those hurt by conflict or forced to leave their homes, at the heart of his call for peace.

He said they make it evident that men are brothers because "despite differences, they cry and laugh the same way, have the same needs, communicate spontaneously, play together."

The painful images of children at the mercy of war and violence, their faces "disfigured by pain and desperation," are a silent appeal for peace, Benedict said.

"Faced with their defenseless condition, all the false justifications for war and violence collapse," the pope said. "We simply must convert to a project of peace, laying down arms of all kinds and committing all together to building a world more worthy of man."

The pope celebrated the Mass in St. Peter's Basilica a week after he was knocked down by a woman on Christmas Eve. He was unhurt in the fall and has kept up his busy holiday schedule.

The Vatican said the woman was mentally unstable and identified her as 25-year-old Susanna Maiolo, a Swiss-Italian national. She remains in a clinic for treatment.

In his homily, Benedict also renewed his call to protect the environment, saying that the degradation of man leads to the degradation of the planet.