'Spooky': Discoveries of mass graves worldwide stir ghosts of hidden histories

The latest discovery in Canada involves the former Marieval residential school in eastern Saskatchewan that had hosted indigenous children between 1899 and 1997 before being demolished.

It comes just weeks after the nation was rocked by the discovery of the remains of 215 schoolchildren at another former indigenous residential school in Kamloops, British Columbia.

Some 150,000 Native American, Metis and Inuit children were forcibly enrolled up until the 1990s in 139 of these residential schools in Canada, where they were isolated from their families, language and culture, and physically and sexually abused by staff and teachers.

More than 4,000 students died in the schools, according to a commission of inquiry that concluded Canada had committed "cultural genocide" against indigenous communities. 

The Spanish government in March approved a special fund to exhume graves at the Valley of the Fallen, a vast complex near Madrid where some 33,000 victims of the Spanish Civil War are buried.

Built between 1940 and 1958 partly by the forced labour of political prisoners, the imposing basilica and mausoleum were initially intended for those who had fought for the fascist dictator General Franco.

But in 1959 the remains of many Republican opponents were moved there from cemeteries and mass graves across the country without their families being informed.

When Franco died in 1975, authorities opted to draw a veil over the past for fear of further conflict.

Socialist Prime Minister Pedro Sanchez has made the rehabilitation of Franco's victims a priority since coming to power in 2018.

Campaigners estimate that more than 100,000 dead from the war and its aftermath remain buried in unmarked graves across Spain -- a figure exceeded only by Cambodia, says Amnesty International.

In January a six-year-long inquiry concluded that 9,000 children had died in state- and Catholic Church-run homes for unmarried women and their babies in Ireland that were still operating as recently as 1998.

The Commission of Investigation into Mother and Baby Homes was established in 2015 after an amateur historian uncovered evidence of a mass grave of infants at one such home in the town of Tuam.

Catherine Corless proved that 796 children, from newborns to a nine-year-old, died at the home run by Catholic nuns between 1925 and 1961.

There are no burial records, leading many to believe a mass grave in a disused septic tank discovered in 1975 near the home was the children's final resting place.

Plans are under way to excavate the site.

Archaeologists dug up the remains of more than 1,500 people, many of them believed to have died in an epidemic, who were buried in a 19th century mass grave that is being excavated for a city development project in Osaka in western Japan.

The Umeda Grave, one of seven historical burial sites in Japan's bustling merchant city of Osaka, was unearthed as part of a redevelopment project near a main train station. The more than 1,500 remains were found during excavations that began in September 2019, following an earlier 2016-2017 study that dug up hundreds of similar remains at adjacent locations, according to Yoji Hirata, an official at the association.

A forensic team in Tulsa unearthed 11 coffins while searching for victims from the 1921 massacre in which hundreds of Black residents were killed.

The mass grave was discovered in an area of the city’s Oaklawn Cemetery where records and research suggested that as many as 18 victims would be found. 

The 1921 massacre began after white people tried to lynch a young Black man over allegations that he had attacked a young white woman who was an elevator operator at a drugstore. The man was cleared, but when a group of white men converged with a group of Black men at a police station, shots were fired and a fight broke out.