ALFACAR, Spain — Forensic experts on Wednesday began exhuming a mass unmarked grave that could hold the remains of the acclaimed poet Federico Garcia Lorca, in a milestone in Spain's drive to address the legacy of its 1936-39 civil war.

Working under a tent-like structure, the team started preliminary work staking out and cleaning surface soil at the site in southern Spain in preparation for digging in earnest, said Sara Gil, an archaeologist who is a member of the team.

"The excavation work has begun. I cannot say anything else," Gil told reporters.

Maribel Brenes, president of a local association of relatives of war-time missing, said the exhumation will get under way in earnest later in the week.

It is not clear if the writer's remains will ever be identified, however, because his family opposes the exhumation. The goal of the digging is to find and identify the remains of several men who, like Garcia Lorca, were executed in the opening days of the civil war and are believed to be buried along with him in the same grave.

The work is being done on a remote hillside area near the southern city of Granada, near where the men were killed by members of a militia loyal to Gen. Francisco Franco.

The war, which still divides Spaniards 70 years after it ended, pitted Franco-led rightist forces that rose up against an elected leftist Republican government and eventually prevailed, installing a dictatorship that lasted until Franco's death in 1975. The conflict and ensuing hardship left an estimated half a million people dead.

Both sides committed atrocities against civilians but Franco's government is known to have done a thorough tally of civilians executed by anti-Franco militia and gave them proper burials. Spanish judge Baltasar Garzon says 114,000 civilians killed by Franco forces were never accounted for.

Garcia Lorca's case is one of the most celebrated of these because he was Spain's most acclaimed 20th-century poet and a cultural icon.

A group called the Association for the Recovery of Historic Memory has been working since the late 1990s to help Spaniards locate the graves of loved ones who went missing during the war. So far, the group says it has identified about 1,700 people.

Garcia Lorca was not a member of a political party, but he was identified with the leftist republic Franco rose up against.

A contemporary and friend of artist Salvador Dali and film director Luis Bunuel, Garcia Lorca already was famous in Spain and abroad at the age of 38. But his works, as well as the fact that he was a homosexual, greatly irritated the country's right wing and the Roman Catholic Church, and made him a marked man when hostilities broke out in the summer of 1936.