Pope John Paul II urged people across the globe to fight terrorism as Christians celebrated the culmination of Easter, a festival clouded this year by warnings of more terror strikes.
The fears of further terror attacks in Europe and chilling images from Iraq have cast a long shadow over the holiest period in the Christian calendar, which marks the crucifixion and resurrection of Jesus Christ.
John Paul II used his Easter Sunday message to urge mankind to oppose the "inhuman" phenomenon of terrorism and prayed that humanity would find "the courage to oppose in solidarity the many evils that afflict it".
The 83-year-old pontiff, who said the world was "troubled by many threatening shadows", appeared weary from the very beginning of the lengthy mass and spoke haltingly, often grimacing with the effort of his delivery.
Last year, the pope had warned that the US-led invasion of Iraq would drive a wedge between Muslim and Christian cultures. Conflicts in Iraq, the Middle East and Africa again loomed large in his Easter message.
Sunday's celebration, broadcast to millions around the world, was a test for the pope, who is crippled by Parkinson's disease.
Tens of thousands of people gathered in St Peter's Square amid tight security to hear his message and traditional "Urbi et Orbi" (to the city and the world) blessing in 62 languages.
Security was ramped up around the Vatican for the occasion, with 16,000 police and paramilitary troops placed on guard and pilgrims passing through airport-style metal detectors to enter St Peter's Square.
In Iraq, the small Christian community celebrated Easter amid fears over the rising influence of Shiite Muslim fundamentalism, as the patriarch of the Chaldean church appealed for an end to bloodshed in the country.
At the Church of the Holy Virgin in Baghdad, Emmanuel Delly called for an end to the tide of violence. More than 400 people have been killed and 1,000 wounded in the past week of clashes between insurgents and US troops.
US President George W. Bush for his part attended religious services at the US Army's largest base, Fort Hood, Texas.
In the Middle East, several hundred pilgrims attended a mass in Jerusalem's Church of the Holy Sepulchre, said to be built on the spot where Jesus Christ was crucified.
But the celebrations were largely muted with many Palestinian Christians unable to receive Israeli travel permits amid a general lockdown imposed on the occupied territories during what it is also the Jewish Passover holiday.
And the foreign visitors who used to flock in their thousands to the holy city over Easter were largely absent after more than three years of violence between Israelis and Palestinians.
In Moscow, Russian President Vladimir Putin celebrated the main Orthodox Easter service at an overnight ceremony led by Patriarch Alexy II.
Unusually, the Orthodox and Roman Catholic Churches this year mark Easter on the same day, and Alexy and Pope John Paul exchanged congratulatory messages.
In Africa, Ugandan religious leaders called for dialogue between the government and the rebel Lord's Resistance Army (LRA) to end almost two decades of fighting in the north of the country.
Violence invloving the LRA, whose stated aim is to set up a regime based on the biblical Ten Commandments, has killed or maimed tens of thousands of people and displaced some 1.5 million others.
And Nigerian President Olusegun Obasanjo used his Easter Sunday message to call for good will -- and for extra vigilance, less than two weeks after an alleged coup plot was reported in the west African country.
"Like Jesus Christ, we must think less of ourselves and more of others by shunning corruption, violence, hate, greed and intolerance," Obasanjo said.
In the war-scarred Balkans, hundreds of thousands of Catholic Croatians celebrated Easter Sunday alongside the minority Orthodox ethnic Serbs.
Catholic Archibishop Josip Bozanic asked believers at Zagreb cathedral to pray for world peace, while Orthodox Bishop Jovan Pavlovic urged a congregation in downtown Zagreb to live in love with other communities.
And thousands of people joined in series of traditional Easter Sunday peace marches in Germany -- including a reported 7,000 who rallied to protest at plans to build a bomb test site in the eastern state of Brandeburg.
Elsewhere in Europe, where jitters persisted one month after the Madrid bombings, Copenhagen station was evacuated following a false bomb alert, sparked when a tourist left her rucksack unattended on a bench.
Meanwhile in Indonesia's restive Poso district, a gunman opened fire on a choir practice in a church over the Easter weekend, wounding seven people.
Poso, in Central Sulawesi, has seen intermittent violence between its Muslim and Christian communities since 2000.
The crucifixion and resurrection of Christ are central to Christian faith, which believes that God took on human form and suffered a humiliating and agonising death in order to save mankind from sin.
While the Passion is today ritually celebrated in the West, it is still physically re-enacted in some places, such as the Philippines, where dozens of young men scourged themselves in the village of Cutud on Friday and 13 were briefly nailed to wooden crosses in a ceremony frowned on by the Catholic Church.