The remains of 215 children have been discovered on the grounds of a former boarding school set up more than a century ago to assimilate Canada's indigenous peoples, according to a local tribe.
A specialist used ground-penetrating radar to confirm the remains of the students who attended the school near Kamloops, British Columbia, the Tk'emlups te Secwepemc tribe said in a statement late on Thursday.
"Some were as young as three years old," chief Rosanne Casimir said, calling it "an unthinkable loss that was spoken about but never documented" by school administrators.
Its preliminary findings are expected to be released in a report next month, she said.
In the meantime, the tribe is working with the coroner and museums to try to shed further light on the discovery and find any records of the deaths.
It is also reaching out to the students' home communities across British Columbia and beyond.
The "distressing" discovery of the remains "breaks my heart," Prime Minister Justin Trudeau said in a Twitter message.
"It is a painful reminder of that dark and shameful chapter of our country's history," he said.
The news that remains were found at the former Kamloops residential school breaks my heart - it is a painful reminder of that dark and shameful chapter of our country's history. I am thinking about everyone affected by this distressing news. We are here for you. https://t.co/ZUfDRyAfET— Justin Trudeau (@JustinTrudeau) May 28, 2021
His comments were echoed by Crown-Indigenous Relations Minister Carolyn Bennett who also offered government support to the families and indigenous communities for their "healing as we honour loved ones lost."
The Kamloops Indian Residential School was the largest of 139 boarding schools set up in the late 19th century, with up to 500 students registered and attending at any one time.
It was operated by the Catholic church on behalf of the Canadian government from 1890 to 1969.
Some 150,000 Indian, Inuit and Metis youngsters in total were forcibly enrolled in these schools, where there were incidents of physical and sexual abuse and students were stripped of their culture and language.
Today those experiences are blamed for a high incidence of poverty, alcoholism and domestic violence, as well as high suicide rates, in their communities.
A truth and reconciliation commission identified the names of, or information about, at least 3,200 children who died from abuse or neglect while attending a residential school. The exact number remains unknown.
At the Kamloops school, the principle in 1910 had raised concerns that federal funding was insufficient to properly feed the students, according to the Tk'emlups te Secwepemc statement.
Ottawa formally apologised in 2008 for what the commission later termed a "cultural genocide" as part of a Can$1.9 billion (€1.29 billion) settlement with former students.