Pope Francis agreed to meet in December with Indigenous Canadians who went through the infamous residential schools and demand an apology from the Catholic Church for the abuse and death of thousands of Indigenous children.

The Canadian Conference of Catholic Bishops said the pope had invited the delegations to the Vatican and would meet separately with three groups — First Nations, Métis and Inuit — from Dec. 17-20. He will then preside over a final hearing with the three groups on Dec. 20, the conference said in a statement.

The Vatican did not confirm the visit on Wednesday, but the Holy See’s news portal reproduced the bishops’ statement that the visit depends on the pandemic. He adds that the delegations will be made up of residential school survivors, older and younger Indigenous people, Indigenous community leaders and bishops.

In recent weeks, researchers using ground-penetrating radar have reported finding hundreds of unmarked graves at the sites of two residential schools for Indigenous children. The discovery of more than 600 rumbas at one school and 250 at another has revived calls, including from Prime Minister Justin Trudeau, for a formal apology from the Pope.

From the 19th century to the 1970s, more than 150,000 Aboriginal children were forced to attend publicly funded Christian residential schools in order to assimilate them into Canadian society. Thousands of children died of disease and other causes, and many never returned to their families.

About 75% of the 130 residential schools were run by Catholic mission organizations, the rest by the Presbyterian, Anglican and United Church of Canada churches.

The government officially apologized in 2008, and the three Protestant churches have done the same.

The Catholic bishops in their statement made no mention of the call for a papal apology, saying only that Francis was “deeply interested in hearing directly from indigenous peoples.”