It's thought to date back to the Franco regime

Forensic archaeologists in Spain have found the remains of some 100 people near Valencia.

They're believed to have been executed by the Franco regime at the end of Spain's Civil War eight decades ago.

Experts unearthed four fractured skulls on Tuesday amid a mass of bones and decaying clothes.

A volunteer uses a brush to clean the bones of a victim before an exhumation inside a mass grave at the cemetery of Paterna, near Valencia in Spain | Image: Emilio Morenatti/AP/Press Association Images

It's the latest among many similar efforts led in the past decade by relatives of at least 114,000 or so victims of the civil war, and the four decades of Francoism that followed.

Their deaths were never officially investigated.

A skull with other bones of a victim's body is classified by anthropologists following an exhumation of a mass grave at the cemetery of Paterna, near Valencia in Spain | Image: Emilio Morenatti/AP/Press Association Images

Graveyard number 112 - where two batches of 50 prisoners were inhumed months after the war ended in April 1939 - was the latest to be opened in the town of Paterna.

After days of careful digging underneath a layer of ordinary, casket-burials, piles of skeletons emerged.