NAPLES — Despite protests that ended with three people arrested, as well as a campaign asking the Vatican to revisit the decision, a Chilean bishop mentored by the country’s most notorious sex abuser priest took possession of his new diocese on Saturday.

The appointment by Pope Francis has led many observers to question the pontiff’s commitment to tackling the scandals of clerical sex abuse and hold those who stood by accountable for their inaction.

An estimated 4,000 people dressed in black as a sign of mourning gathered in front of the cathedral of the diocese of Osorno, Chile, to demand that Bishop Juan Barros Madrid, former military chaplain, not take possession.

A video of the event posted online shows the crowd throwing objects at the prelate, pushing him, and trying to stop him from entering St. Mathew’s Cathedral, despite strong security measures.

“I’ve never seen anything like this,” a layperson who was inside the church told Crux. “It was sad to see the church I pray at every day reduced to a battlefield between those who supported the prelate and those who didn’t.”

Requesting to remain unnamed because he has ties with the diocese, the person said that while Barros was celebrating the Mass, many kept screaming “Pedophile!” and “Get out!” The situation escalated to the point that the celebration had to be cut short, skipping the homily, Communion, and other parts of the liturgy.

Barros had to be escorted out of the church after the ceremony.

Local newspapers reported that the police chief, Leonardo Castillo, told journalists that at least three people had been detained for disorderly conduct.

Since Barros’s appointment was announced last January, it has been criticized by elements of the local community because of ties Barros had with the Rev. Fernando Karadima, a priest the Vatican condemned in 2011 to a life of “solitude and prayer” after being found guilty of sexually abusing several devoted followers during the 1980s and the 1990s.

Three of Karadima’s victims, Juan Carlos Cruz, James Hamilton, and José Andrés Murillo, have accused four Chilean prelates, including Barros, of covering up for Karadima and of being present while he abused them.

The victims are in a legal battle with the diocese of Santiago de Chile, demanding, among other things, an apology from the Church and financial compensation of $700,000.

The victims recently released a statement saying that “as survivors of the abuse by Karadima, and the complicity of Bishop Barros, we are accustomed to the blows we have received from the Chilean hierarchy, but never directly from the Holy Father.”

Cruz told Crux in an e-mail that “this man [Barros] saw our abuses. He was there, we testified to it, and we were ignored many times. We now know that he was a disastrous man.”

Saturday’s ceremony was attended by a dozen of the country’s more than 50 bishops and almost 20 of the diocese’s 35 priests.

Cardinal Ricardo Ezzati, archbishop of Santiago de Chile and president of Chile’s Bishops Conference, wasn’t present because of a previous appointment.

Talking to Chile’s Las Últimas Noticias (“The Latest News”), on Friday, Barros, who has denied all charges through a letter made public earlier in the week, said that he had “a strong feeling of hope, hope for the future.”

“I believe that in the end the fact that we’re all members of one Church will prevail, and we’ll follow the word of the Holy Father,” Barros said.

No criminal or canonical procedures were ever launched against Barros. To date, the Vatican has made no statement in response to the criticism of his appointment.

The Organization of Laymen and Laywomen of Osorno is calling for the new bishop to step aside.

Juan Carlos Claret Pool, leader of the movement, told Crux that a bishop should have moral authority over the clergy, the laity, and civil society, “which Barros doesn’t have.”

Because of this, he said, they plan to continue working and to remain “mobilized.”