Updated

Crews on Monday began digging up an unmarked grave believed to be holding victims of the Spanish Civil War, in the country's first such court-ordered exhumation.

The Association for the Recovery of Historic Memory said volunteers were digging up part of a cemetery in the northwestern town of Santa Marta de Tera in search of the bodies of four men believed to have been assassinated by a right-wing militia at the beginning of the 1936-39 war.

The excavation was the first to be ordered by a judge since the association began searching a decade ago for the bodies of tens of thousands of people believed to have been killed by supporters of dictator Francisco Franco and dumped in unmarked graves during the war and the dictatorship that followed.

The association has long demanded that the Spanish government and local authorities become involved in the search, but to date has had to carry out its own excavations.

That is because many people, politicians and local authorities oppose such a search, arguing that such crimes were covered by an amnesty passed in 1977 — two years after Franco died — at a time when Spain was moving to restore democracy and focus on rebuilding the ruined nation, rather than on reopening old wounds.

Emilio Silva, the president of the Association for the Recovery of Historic Memory, said that even though Spain's Socialist government passed a landmark bill in 2007 which formally denounced the Franco regime and made symbolic amends to victims, it pushed aside the issue of the missing.

"The judge's order is a sign that times are changing, and it's about time," said Silva. "The judicial system has to play a role in this."

The order permitting the excavation was issued by Judge Tania Chico in the nearby town of Benavente. She issued the order after interviewing relatives of the victims and authorized DNA tests.

The association now hopes to find the bones of the people they believe to be there and then confirm their identity and give them a proper burial.

The Benavente ruling follows the launching of an investigation last year into the Civil War's missing by Spain's best-known judge, Baltasar Garzon. He has since removed himself from the case because of a jurisdiction dispute, but he urged provincial courts to press ahead with the probe.

Silva said confusion over who can authorize exhumations has led many provincial courts to refuse to order them.

Garzon estimated more than 114,000 people disappeared between the start of the war until 1952, when he said repression under the Franco regime eased.

Historians estimate half million people died in the war itself.