Cesar Milani, commander in chief of the army between 2013 and 2015 during the leftist presidency of Cristina Kirchner, is accused of participating in an operation to kidnap and torture suspected dissidents Pedro and Ramon Olivera in 1977.

The trial is taking place in the capital of the western province of La Rioja, where the events allegedly took place.

At the time, Milani -- now 64 -- was a young lieutenant.

The former army chief is also accused of the forced disappearance of a soldier in 1976, for which he is facing a separate trial in September.

Others charged in the case are being tried for aggravated homicide, illegal trespass, deprivation of liberty and torture, according to the Judicial Information Center.

Military officers received an amnesty when Argentina returned to democracy in 1983 but it was later annulled under the late Nestor Kirchner, who was president from 2003-2007.

Milani, who became army chief in the subsequent government of Kirchner's wife Cristina, is being held in the Campo de Mayo military base in Buenos Aires.