Hundreds of human skulls and bones have been uncovered in a hidden shelter accessed through a secret passage beneath the Mor Dimet Church in the village of Arbo, located in the Nusaybin district of Mardin (Mêrdîn).

The remains, filmed for the first time by Mezopotamya Agency, are believed to belong mostly to women and children, and are thought to belong to the victims of a mass killing during the 1915 Seyfo Massacre, which targeted the Assyrian-Syriac people.

The shelter is reached through a narrow and dark passage. Inside, bones and skulls are lined along the walls, bearing witness to the horrific past hidden within. However, no official investigation has been carried out to date.

Villagers say they have known about the shelter for years but chose to remain silent due to fears of displacement and massacre.

The village of Arbo, which has been emptied three times throughout its history, was most recently evacuated by the state in the 1990s for "security reasons."

The Syriac residents began returning from Europe in 2001 to rebuild the village. Despite this, no official action has yet been taken regarding the mass grave found beneath Mor Dimet Church.

The Assyrian-Syriac-Chaldean genocide, also known as Seyfo, occurred during World War I. Estimates of the total death toll vary, with some reports placing it between 180,000 and 275,000. More recent estimates suggest the number may be even higher.