Pope Benedict XVI offered an Easter prayer Sunday for diplomacy to prevail over warfare in Libya and for citizens of the Middle East to build a new society based on respect.
He also called on Europeans to welcome refugees from North Africa.
"In heaven, all is peace and gladness. But, alas, all is not so on Earth!" the pope lamented as he delivered the traditional "Urbi et Orbi" message from the central balcony of St. Peter's Basilica to a crowd of more than 100,000 that overflowed from St. Peter's Square.
"In the current conflict in Libya, may diplomacy and dialogue replace arms, and may those who suffer as a result of the conflict be given access to humanitarian aid," he said.
This year, Easter fell on the same day in the Orthodox and Roman Catholic church calendars, and celebrants marked the occasion all over the world. In Washington, President Obama and his family attended Easter services at a church founded in 1863 by freed slaves.
At the Vatican, the pope, referring to North Africa and the Middle East, prayed that all citizens, especially young people, would "work to promote the common good and to build a society where poverty is defeated and every political choice is inspired by respect for the human person."
Uprisings, repression and civil warfare have triggered an exodus of people to Italian shores as well as other countries in the region. Europe has been split over whether to accept or deport tens of thousands of migrants, many of them from Libya and elsewhere in northern Africa.
Benedict rallied to the side of refugees, urging people of good will to "open their hearts to welcome them."
The 84-year-old Benedict's voice cracked at times during the Mass, but he ended his two-hour appearance Sunday by reading aloud holiday greetings in 65 languages.
Some 41,000 potted plants lined the square, including 10,000 narcissus plants, many of them in yellow and white, the official Vatican colors, arranged in neat rows up the slope toward the altar.
In Jerusalem, Orthodox and Roman Catholics worshipped at the Church of the Holy Sepulcher, revered as the site of Jesus' Good Friday crucifixion and burial and of his resurrection on Easter Sunday. Protestants held their own ceremonies outside the walled Old City at the Garden Tomb, which some identify as the site of Jesus' burial.
In Cagliari, Sardinia, an Easter lunch of Sardinian cheese, pasta and lamb was served by Caritas, the Catholic charity, to some 20 Tunisians, the Italian news agency ANSA reported from the island. The diners were some of the more than 26,000 Tunisians who have clandestinely entered Italy since unrest in their homeland in January.
In Washington, Obama and his family attended Easter service Sunday at Shiloh Baptist Church.
The first family entered the church to a round of applause as members of a choir sang "Total Praise."
Obama shook a few hands and hugged some members of the congregation as he and his wife, Michelle, and their daughters, Malia and Sasha, walked to a second-row pew.
In New York City, this year's Easter Parade stretched a dozen city blocks up and down Fifth Avenue from St. Patrick's Cathedral, the seat of New York's Roman Catholic Archdiocese. The church was packed for a noon Mass celebrated by Archbishop Timothy Dolan.