Christians celebrated Easter around the world Sunday, but with reminders of violence and politics.

In his second Easter message since becoming pontiff, Pope Francis prayed for an end to conflicts in Iraq, Israel, the Central African Republic, Nigeria, South Sudan, Venezuela and Ukraine.

He delivered his speech from the central balcony of Saint Peter's Basilica.

"We pray in a particular way for Syria, that all those suffering the effects of the conflict can receive needed humanitarian aid and that neither side will again use deadly force, especially against the defenseless civil population, but instead boldly negotiate the peace long awaited and long overdue," the pope said.

Security was tight in Jerusalem on Sunday, a day afater tensions escalated when Israeli security forces halted Palestinian Christians who took part in a pre-Easter procession in the Old City.Jerusalem: Tight security

Robert Serry, the U.N. special coordinator for the Middle East peace process, was among the group trying to walk together on what was Holy Saturday.

"I call on all parties to respect the right of religious freedom, granting access to holy sites for worshippers of all faiths and refraining from provocations, not least during the religious holidays," Serry said.

But Israeli Foreign Ministry spokesman Yigal Palmorcalled the incident a "non-event." He told the Jerusalem Post that police were trying to limit the number of those packed into the church and the narrow streets around it.

Boston: A blessing before the marathon

In the United States, Cardinal Sean O'Malley will offer a blessing for runners in the Boston Marathon at the end of Easter Sunday Mass at the Cathedral, CNN affiliate WJAR-TV said.

Though an annual part of the race buildup, the Cardinal's blessing will have extra meaning this year. The city is marking the one-year anniversary of the bombings that killed three people and wounded at least 264 others.

This year's marathon is Monday. Other Boston churches will offer special blessings.

British royals, Obama celebrate Easter

Queen Elizabeth II will attend Easter Mass at St. George's Chapel at Windsor Castle. Meanwhile, on the other side of the planet, the Duke and Duchess of Cambridge continue their tour of Australia.

President Obama wished the American people a happy Easter on Saturday in his weekly address.

"For me, Easter is a story of hope -- a belief in a better day to come, just around the bend," he said. "So to all Christians who are celebrating, from my family to yours, Happy Easter. And to every American, have a joyful weekend."

He celebrated Passover earlier this week with the fifth Seder at the White House. Obama is the first president to host a Seder dinner while in office.