VATICAN CITY - Iraqi Christians celebrated a somber Christmas in a Baghdad cathedral stained with dried blood, while Pope Benedict XVI - in a holiday address laced with worry for the world's Christian minorities - exhorted Chinese Catholics to stay loyal despite restrictions on them.

Saturday's grim news seemed to highlight the pope's concern for his flock's welfare. In northern Nigeria, attacks on two churches by Muslim sect members claimed six lives, while bombings in central Nigeria, a region plagued by Christian-Muslim violence, killed 32 people, officials said.

In the Philippines, which has Asia's largest Catholic population, 11 people were injured by a bombing during Christmas Mass in a police chapel. One of those hurt was a priest. The attack occurred on Jolo island, a stronghold of al-Qaeda-linked extremists.

But joy seemed to prevail in Bethlehem, the West Bank town where Jesus was born, which bustled with its biggest crowd of Christian pilgrims in years.

The suffering of Christians around the world framed much of the pontiff's traditional Christmas Day Urbi et Orbi message (Latin for to the city and to the world). From the central balcony of St. Peter's Basilica, Benedict, bundled up in an ermine-trimmed crimson cape against a chilly rain, delivered his assessment of world suffering.

His exhortation to Catholics who have risked persecution in China highlighted a spike in tensions between Beijing and the Vatican over the Chinese government's defiance of the pope's authority to name bishops.

The pope has also been distressed by Chinese harassment of Rome-loyal bishops who did not want to promote the state-backed official Catholic church.

"May the birth of the savior strengthen the spirit of faith, patience, and courage of the faithful of the church in mainland China, that they may not lose heart through the limitations imposed on their freedom of religion and conscience," Benedict said, praying aloud.

Chinese church officials did not immediately comment. On Friday, one said the Vatican bore responsibility for restoring dialogue after it criticized leadership changes in China's official church.

Persecution of Christians has been a pressing concern at the Vatican of late, especially over its dwindling flock in the Middle East. Christians make up only about 2 percent of the population in the Holy Land today, compared with about 15 percent in 1950. Earlier this month, Benedict denounced a lack of freedom of worship as a threat to world peace.

In Iraq, Christians have faced repeated violence by extremists intent on driving them out of the country.

At Our Lady of Salvation Church in Baghdad, bits of dried flesh and blood remained stuck on the ceiling, grim reminders of the Oct. 31 attack during Mass that killed 68 people. Black cassocks representing the two priests who perished in the al-Qaeda assault hung from a wall. Bullet holes pocked the walls of the church, now surrounded by concrete blast barriers.

Reflecting the pope's hope that Christian minorities can survive in their homelands, Archbishop Matti Shaba Matouka told the 300 worshipers: "No matter how hard the storm blows, love will save us."

After the October siege, about 1,000 Christian families fled to the relative safety of northern Iraq, according to U.N. estimates.

More than 100,000 pilgrims poured into Bethlehem since Christmas Eve, twice as many as last year, Israeli military officials said, calling it the highest number of holiday visitors in a decade.

It's "a really inspiring thing to be in the birthplace of Jesus at Christmas," said Greg Reihardt, 49, of Loveland, Colo.

Benedict said he hoped Israelis and Palestinians would be inspired to "strive for a just and peaceful coexistence."