An indigenous nation in Canada says it has found 751 unmarked graves at the site of a former residential school in Saskatchewan. The Cowessess First Nation said the discovery was "the most significantly substantial to date in Canada,” reported BBC. It comes weeks after the remains of 215 children were found at a similar residential school in British Columbia. Marieval Indian Residential School was operated by the Roman Catholic Church from 1899 to 1997 in the area where Cowessess is now located in southeastern Saskatchewan. It is not yet clear if all of the remains are linked to the school. It was one of more than 130 compulsory boarding schools funded by the Canadian government and run by religious authorities during the 19th and 20th Centuries with the aim of assimilating indigenous youth. An estimated 6,000 children died while attending these schools, due in large part to the squalid health conditions inside, reported BBC. Students were often housed in poorly built, poorly heated, and unsanitary facilities. Physical and sexual abuse at the hands of school authorities led others to run away, reported BBC. Last month, the Cowessess began to use ground-penetrating radar to locate unmarked graves at the cemetery of the Marieval Indian Residential School in Saskatchewan. The announcement on June 24 marked the first phase of the search efforts. Watch the video to know more.