Leaders of a First Nation in Canada said Thursday they have found indications of at least 751 unmarked graves near the site of a former residential school in Saskatchewan, the second such announcement here in less than a month as the country reckons with the devastating legacy of one of the darkest chapters of its history. Cowessess First Nation Chief Cadmus Delorme said the discovery was made near the grounds of the former Marieval Indian Residential School in the southeastern corner of the prairie province, confirming the stories of Indigenous elders and residential school survivors who had long told stories of a burial site there. Nearly 150,000 Indigenous children were sent to the government-funded and church-run boarding schools, which were set up in the 19th century to assimilate them and operated until the late 1990s. Many children were forcibly separated from their families to be placed in the schools. Canada's Truth and Reconciliation Commission said in a 2015 report that many of the students were subjected to physical and sexual abuse at the schools, which barred them from practicing their traditions and speaking their languages. It said the schools carried out "cultural genocide" and effectively institutionalized child neglect. The commission identified more than 3,000 students who died at the schools, a rate that was far higher than for non-Indigenous school-aged children. Officials say the total number of children who died or went missing at the schools might never be known.