Those arrested include Spanish Monsignor Lucio Vallejo Balda and Francesca Immacolata Chaouqui, who served on the pope's special commission on economic reform.
Days before the release of books that purportedly contain revelations of corruption, the Holy See charged a monsignor and a public relations expert with leaking confidential information to the media.
The Catholic Church in the U.S. has been aging, along with its dwindling priestly ranks. But in the increasingly secular world, there's been a recent uptick in younger men studying to become priests.
Pope Francis' social media feeds have blossomed while he's been pontiff, allowing followers to access his messages via Twitter, YouTube and also an app on their smartphones.
Pope Francis is set to visit a Catholic school in New York City that used to have a sponsoring church. The parish was closed in 2007 in a region that has been a traditional Catholic stronghold.
The pope will canonize 18th-century Spanish priest Junipero Serra in the U.S. later this month. But descendants of the Mission Indians in California say Serra destroyed their traditional way of life.
John Paul II urged openness during his 1998 tour of the island, but progress has been slow in the 17 years since. Pope Francis, who helped reopen U.S. relations, arrives next week.
About 40 percent of U.S. Catholics are foreign-born or the children of immigrants. The change is having profound effects, from reviving dying parishes to shifting the church's geographical center.