Vatican City - Pope Benedict XVI on Sunday lamented "suffering" in the world's strife-torn and poorest regions as millions across the globe marked Easter, the holiest day in the Christian calendar.
"How many wounds, how much suffering there is in the world! Natural calamities and human tragedies that cause innumerable victims and enormous material destruction are not lacking," the head of the Roman Catholic Church said in his traditional Easter address.
"I am thinking of the scourge of hunger, of incurable diseases, of terrorism and kidnapping of people, of the thousand faces of violence which some people attempt to justify in the name of religion ..." he said.
Speaking from the loggia of St Peter's Basilica to a crowd of tens of thousands, the pope evoked the plight of victims of last week's tsunami in the Solomon Islands as well as the ongoing carnage in
Iraq.
He said "nothing positive comes from Iraq" which is "torn apart by continual slaughter as the civil population flees."
The pope rarely speaks about Iraq, where bloodshed continues despite a massive security operation since February 14 to quell daily violence that has killed thousands in the past year alone.
He also expressed "apprehension" at "the conditions prevailing in several regions of Africa," the world's poorest continent, notably Darfur, Somalia and Zimbabwe.
The archbishop of Canterbury, Rowan Williams, the leader of the world's Anglicans, urged Christians to embrace forgiveness and reconciliation, saying they could help resolve conflicts around the world.
Recalling recent progress in the Northern Ireland peace process, where rival Protestant and Catholic parties agreed last month for the first time to share power in the British-run province, Williams said: "Going forward requires us all to learn a measure of openness to discover things about ourselves we did not know, seeing ourselves through the eyes of another."
In Moscow, President Vladimir Putin marked Easter by returning a long-lost icon of Our Lady of Vladimir to Russia's Orthodox Patriarch Alexy II, and pledged to return other religious relics lost in the Soviet era.
Alexy II on his part put aside long-running differences with the Roman Catholic Church to send Easter greetings to Pope Benedict XVI, in a letter quoted by the Interfax news agency Saturday.
"I ... wish you blessed peace, good health and the Risen Saviour's help in your lofty service" on the "ever-joyful holiday of Easter," he said.
For the first time an icon -- a holy work of art venerated by Orthodox Christians -- was placed near the altar as Benedict XVI presided over Easter mass in the Vatican's St Peter's Square.
Celebrations took different forms across the world.
Solomon Islanders prayed for victims of the tsunami while a priest urged the people to take up the task of rebuilding.
"Now is not the time to wait and sit for supplies. Now is time for you to make work, to start and rebuild after the tsunami," Reverend John Pihavaka told his congregation.
Iraq's dwindling Christian minority donned their Sunday best but held quiet festivities, fearful of the bombings and abductions terrorising Baghdad's streets.
In Jerusalem, thousands of worshippers from five Christian faiths celebrated Easter at the traditional site of Jesus's death, burial and resurrection -- the city's contested Holy Sepulchre Church.
Millions of worshippers crammed into churches in Greece around midnight Saturday to hear priests announce that "Christ is risen." Easter celebrations are the biggest religious festival in Greece, where 97 percent of the population is Orthodox.
In Ukraine, Easter had political undertones with hundreds of protesters against President Viktor Yushchenko celebrating with traditional cakes and eggs sporting the blue-and-white colours of Prime Minister Viktor Yanukovych, who has defied Yushchenko's order to dissolve parliament.
There were demonstrations in Germany, with about 12,000 gathering in the eastern city of Fretzdorf for a traditional pacifist Easter march. This year's target was government plans for a military bombing range north of Berlin.
More than 1,000 people also marched about 50 kilometres (31 miles) between Duisburg and Dortmund to protest against the participation of German troops in military missions abroad.
Easter was celebrated with great fervour in Poland, where more than 90 percent of the population is Roman Catholic, prompting one priest to remark that his church might need to be enlarged for the growing numbers of worshippers.
US President George W. Bush marked Easter Sunday by attending church at a Texas military base and said he had prayed for peace and for the safety of US troops.