(CNN) -- Belgian church officials will begin interviews Tuesday in their inquiry into allegations of sexual abuse of children by clergy and others working for the church from the 1950s into the late 1980s.
The interviews are a follow-up to a church-backed investigation that detailed hundreds of assertions of sexual abuse.
It was led by Dr. Peter Adriaenssens, who is both a church investigator and a psychiatrist.
"From the mistakes of the past, we wish to take the necessary lessons," said Archbishop Andre-Joseph Leonard, the head of the Catholic Church in Belgium, on Monday. "In the interviews that will be conducted from tomorrow, we will consider the relevant reflexions and proposals of Professor Adriaenssens."
The process will take time, because "it is impossible to try to resolve these traumatic experiences too quickly," Leonard said.
"We want to commit ourselves to giving the maximum support for the victims," he said. "We must listen to their questions in order to restore their dignity and help heal the suffering they have endured."
A Vatican spokesman said Monday that Pope Benedict XVI feels much pain after the revelations.
"The publishing of this report is a new cause of pain for us, for the victims," Father Federico Lombardi said.
The Vatican's statement comes in response to Friday's report by the Commission on Church-Related Sexual Abuse Complaints that detailed hundreds of assertions of sexual abuse of children by clergy..
The Commission on Church-Related Sexual Abuse Complaints said it received about 500 reports from alleged victims, about 60 percent of them from males.
It cited 320 alleged abusers, of whom 102 were known to have been clergy members from 29 congregations.
Thirteen of the alleged victims committed suicide, it said.
"We can say that not a single congregation escaped sexual abuse of minors by one or more of its members," the commission said Friday.
"The stories they contain and suffering make us shudder," Leonard said.
The Catholic Church is facing allegations that clergy members abused children in at least half a dozen countries, including the pope's native Germany, as well as Belgium, Ireland, Austria, the Netherlands and the United States.
CNN's Alex Felton and Atika Shubert contributed to this report.