VANCOUVER -- The chief of the Tk'emlups te Secwepemc First Nation says the community wants a public apology after 215 children's remains were found at a former Kamloops residential school.

The band announced last week that the remains of the children, some of whom were young as three, were found using the services of a ground-penetrating radar specialist.

Chief Rosanne Casimir spoke about the tragic discovery on Friday.

"This is only the beginning and there is still so much work yet to be done," Casimir said. "Now is a time that we do some important grieving and healing work in our own community."

Casimir said the community wants a formal apology.

"We do want an apology, a public apology. Not just for us but for the world who also shared in (the suffering)," she said. "Holding the Catholic church to account, there has never been an apology from the Roman Catholics."

Prime Minister Justin Trudeau echoed the demand Friday morning.

“As a Catholic, I am deeply disappointed by the position the Catholic Church has taken now and over the past many years,” he said during a news conference. “I think it’s going to be a really important moment for all of us – particularly Catholics across the country – to reach out in our local parishes, to reach out to bishops, cardinals and make it clear that we expect the church to take up and step up and take responsibility for its role in this. And be there to help in the grieving and the healing including with records that is necessary.”

CTV News spoke to Father Ken Thorson, of the Missionary Oblates of Mary Immaculate, about the role the group played in operating the school. It was given this position by the federal government.

“We were wrong in not doing it sooner, the work of finding out who is buried there, and the work of restoring or repatriating, and the resulting peace or closure that would bring the families,” he said.

Thorson said he was shocked when he learned the remains of 215 children had been found.

“I just continue to be filled with a deep sadness, shame (that) my order’s participation in whatever processes led to the deaths of 215 children,” he said. 

The case has sparked nationwide grief and calls for more searches at other such institutions.

The RCMP says it has opened a file into the case as well.

Staff Sgt. Bill Wallace, the detachment commander with the Tk'emlups Rural RCMP, says officers have been to the site and are working with community members to discuss the next steps.

“The RCMP have acknowledged that we will be leading the investigation and will be working in collaboration with each other,” said Casimir. 

A Truth and Reconciliation Commission report found that at least 4,100 children died in Canada’s residential school system.

Casimir said the band plans to release a report with preliminary findings about its discovery later this month.

Memorials in tribute to the children have popped up across the country since the news broke last week, but Casimir is also calling for a national day of prayer on this upcoming Sunday, June 6. 

Note: CTV News Vancouver initially said this event would be live streamed. However, the organizers of the event requested that the event not be streamed live.

If you are a former residential school student in distress, or have been affected by the residential school system and need help, you can contact the 24-hour Indian Residential Schools Crisis Line: 1-866-925-4419

Additional mental-health support and resources for Indigenous people are available here