(CNN) -- Ernesto Zedillo said in a court filing Friday that his status as Mexico's former president gives him immunity from being prosecuted for a massacre in 1997 that left 45 people dead in a Chiapas village.
Zedillo, who is now employed at Yale University in New Haven, Connecticut, delivered the filing to a U.S. district court in Hartford.
The former president, who was Mexico's leader between 1994 and 2000, denied allegations that his office was in some way responsible for the killings.
"These anonymous accusations that President Zedillo was somehow complicit in the events in Acteal are baseless and outrageous," the statement said. "The December 1997 attack in Acteal was an appalling tragedy. But that tragedy was not the result of an elaborate conspiracy by the Mexican federal government, masterminded by President Zedillo."
He added that he had "inherited the conflict in Chiapas from the prior administration."
Ten anonymous plaintiffs sued Zedillo in September and are seeking about $50 million in damages, according to court documents.
The killings occurred on December 22, 1997, and are considered among the more brutal incidents during an armed conflict that began three years earlier in southern Mexico after Zapatista rebels pushed for more rights for indigenous people.
In 1999, the United Nations Commission on Human Reports issued a report that found that the killings "occurred against a background of long-standing disputes, often over land ownership, which have for decades divided the local indigenous communities."
It identified divisions "further exacerbated by religious and political tensions in Chiapas, stemming from the confrontation between the Government and opposition groups, particularly EZLN (Zapatista Army of National Liberation)."
The report added that clashes between government supporters and those backing Zapatista rebels "claimed a large number of victims" in the region over a five-year span during the 1990s.
Zedillo's administration, analysts say, presided over what is often described as a period that transformed the nation's political landscape, preceding the end to 71 years of one-party rule in 2000 with election of then-PAN party candidate Vicente Fox.