SASKATOON -- Following the discovery of 215 children in a mass grave at a former residential school in Kamloops, B.C., the Federation of Sovereign Indigenous Nations (FSIN) is calling for ground radar searches of residential schools sites in Saskatchewan.

On May 27, the Tk’emlúps te Secwépemc First Nation announced the remains of 215 children had been discovered at the site of a former residential school. They were found over the Victoria Day long weekend using ground-penetrating radar.

On Sunday, the FSIN issued a news release calling for all levels of government to work with the organization to get ground-radar searches done in Saskatchewan.

“We have been informed that sites including the Muskowekwan Indian IRS (Indian Residential School), Onion Lake St. Anthony's IRS, Beauval IRS, Guy Hill IRS, Lebret IRS, Sturgeon Landing IRS and many more have potential mass graves," FSIN Chief Bobby Cameron said. “We respectfully request all First Nations across our traditional lands to join us in this very important lobby effort.”

The last residential school in Canada closed in 1996 in Saskatchewan and Cameron said the provincial and federal governments must do what is right.

“We are consulting with ground penetrating radar experts to help find our lost children,” Cameron said. “However difficult this path will be, we must speak our truth and reclaim our ancestors. We ask all families to come forward with their stories.”

The FSIN said it knows thousands of children did not make it home and were buried without any markers. Cameron said Canada and Saskatchewan have a lot of work to do in the area of reconciliation and addressing the history of residential schools.

On Sunday, the City of Saskatoon, as well as  federal buildings across Canada , lowered flags to half mast out of respect for the children buried in grave site discovered in Kamloops. In a news release, Saskatoon Mayor Charlie Clark said the impact of residential schools on generations of Indigenous people continues to be felt across Canada.

“We are lowering our flags to honour these children and also the thousands of other children who died at residential schools across Canada, many right here in Saskatchewan,” Clark said in a news release.

To honour those children in Kamloops, the city encourages Saskatoon residents, along with members of city council and city employees, to wear orange on May 31.