Pope Benedict XVI is paying tribute to priests, nuns and other missionaries persecuted as they spread the Catholic faith.

Benedict cited the example of a Brazilian priest who was recently slain in Brazil.

Speaking to pilgrims Sunday in St. Peter's Square, the pontiff also called attention to the plight of the Rev. Michael Sinnott, a 79-year-old ailing Irish priest who was kidnapped in the Philippines a few days ago.

Bishops from Africa, where the church is enjoying vigorous growth thanks in part to missionaries, are meeting at the Vatican this month, and the pope recalled that they have spoken of extreme sacrifices made by faithful on that continent.

Some representatives from Africa have told of recent killings of Catholics in Sudan.