A mass grave containing the remains of 215 children has been found in Canada at a former residential school set up to assimilate indigenous people.

The children were students at the Kamloops Indian Residential School in British Columbia that closed in 1978.

The discovery was announced on Thursday by the chief of the Tk’emlups te Secwepemc First Nation.

Prime Minister Justin Trudeau said it was a “painful reminder” of a “shameful chapter of our country’s history”.