In a school facility shuttered in 1978 in the city of Kamloops, a mass graveyard of 215 children, some under the age of 3, was unearthed last month.

According to The Washington Post, unmarked graves have been unearthed near a former indigenous Catholic residential school in Saskatchewan, Canada.

The discovery was "the largest to date in Canada," according to the Federation of Sovereign Indigenous Nations.

Details of results at the old school are likely to be presented by indigenous officials during a news conference on Thursday morning and the number of institutions clarified.

Late May 215 children's bodies were unearthed, which send shock waves across the country, in an old Indian resident school in Western Canada.

Canadian Prime Minister Justin Trudeau and his government colleagues reacted in shock and promised to carry out a comprehensive inquiry.

In Canadian indigenous peoples' boarding schools, between 3200 and 6000 children have died during the entire period of their life, according to different estimates (from the mid-19th century).