Rene Emilio Ponce, a Salvadoran army general and former defense minister accused of ordering the 1989 killings of six Jesuit priests and two others during the country's civil war, died on Monday. He was 64.

Ponce — who faced an investigation in Spain for crimes against humanity — died of heart failure in a hospital in San Salvador, the Defense Department said in a statement.

A U.N. truth commission report released in 1992 found Ponce ordered the killings of the Jesuit priests, their housekeeper and her daughter when Ponce was a colonel in the Salvadoran army. The priests, who worked at the Jesuit-run Universidad Centroamericana, had been suspected of sympathizing with the country's leftist rebel movement.

A U.S. congressional investigation found they had been rousted from their beds and shot by soldiers in the killings, which sparked international outrage.

Ponce was promoted to general the year after the massacre. He was defense minister from 1990 to 1993.

Nine military officials and troops, not including Ponce, who were members of the U.S.-trained Atlacatl Battalion were tried in the slayings in El Salvador, but only two were convicted. Both were freed in 1993 because of an amnesty law passed to accompany a peace treaty ending the war.

In 2009, Spanish Judge Eloy Velasco ordered an investigation of Ponce and 13 other Salvadoran military officials accused of involvement in the killings. No charges were ever filed against Ponce.

More than 75,000 people were killed during the 12-year civil war between leftist guerrillas and a succession of U.S.-backed rightist governments. That war ended in 1991.

Many of the victims were civilians suspected of leftist sympathies slain by death squads linked to the military. Among them were a number of Roman Catholic priests and nuns.