BUENOS AIRES, Argentina — International and Argentine activists on Monday called on Pope Francis to ensure that his “zero tolerance” pledge against sexual abuses by clergy is enforced in his homeland and demanded a trial for those accused of raping deaf and mute children at a Catholic school.

Prosecutors say that members of the clergy abused at least 20 children at the Provolo Institute in Mendoza province. The case has caused a worldwide uproar and more than a dozen people face charges.

The Argentine group Church Without Abuses and the international organizations Ending Clergy Abuse and BishopAccountability.org met with alleged victims Monday and criticized the lack of justice in a case that began more than two years ago.

At least 20 children say they were abused at the Provolo Institute by priest Nicola Corradi, priest Horacio Corbacho and three other men, who were arrested in 2016.

Dozens of students at another branch of the institute in Italy say they were similarly abused for decades, some allegedly by Corradi.

Both men are facing a preliminary hearing in Argentina, but the activists complain the process is taking too long.

“We came to Mendoza to show solidarity with the Provolo victims and echo their cry for justice,” said Anne Barrett Doyle of the online resource Bishop Accountability.

“Pope Francis owes them a personal apology for his complicity and silence. The Italian victims warned him for years that Corradi and others were working with children in Argentina. The pope did nothing.”

The Italian Provolo students went public with tales of abuse in 2009 and named names. The Vatican ordered an investigation and sanctioned four priests, but Corradi apparently never was sanctioned.

The Verona diocese apologized to the Italian students in 2012. The students again accused Corradi, who was then living in Argentina, in a 2014 letter to the pontiff and the Verona bishop, but the Vatican still took no action.

In 2016, a Vatican official said Francis wanted to assure the victims that the church was taking measures to protect children and prevent sexual abuse.

Unlike the Verona case, the statute of limitations has not expired for the alleged crimes in Mendoza.

A member of the Mendoza prosecutor’s office said that 11 preliminary hearings are being carried out, and that “the process has been long” in part because so many people have been charged and there is so much evidence to review. The source spoke on condition of anonymity due to lack of authorization to comment publicly.

Monday’s meeting between activists and alleged victims was part of a campaign urging Francis to visit his homeland to ensure the Catholic Church punishes the crimes and doesn’t protect perpetrators. Francis hasn’t visited Argentina since becoming pope in 2013.

In Argentina there is no official registry of judicial complaints about abuses committed by members of the clergy.

But BishopAccountability.org says that in Argentina, 96 priests, brothers and nuns have been publicly accused of abusing minors.

Doyle also said that the pope should investigate Mendoza Archbishop Marcelo Colombo, who she said “is refusing to provide information about the Provolo abusers to prosecutors and defense attorneys.” Colombo told reporters last year that he was willing to help the victims.

The AP compiled a list of 66 priests, nuns and other religious workers who, between 2001 and 2017, were accused of abusing dozens of people, most of them children. The figure was obtained from victims’ testimonies, judicial and ecclesiastical documents, and local media reports corroborated with the BishopAccountability.org database. In several cases there were no canonical or judicial investigations.

Associated Press journalist Paul Byrne contributed to this report.