Three former Argentine military officers were sentenced to life for crimes against humanity Monday over the execution of 16 guerrillas four decades ago, a senior judicial official said.

"The court sentenced to life in prison the three military officers for 16 aggravated homicides, while two were acquitted. The circumstances were described as crimes against humanity," court director Andrea Gualde told reporters in the southern town of Rawson.

The three military staff sentenced over the killings in 1972 were former officers Luis Sosa, Emilio Del Real and Carlos Marandino. Ruben Paccagnini and Jorge Bautista were acquitted, Gualde said.

During the regime of the late General Alejandro Lanusse, 29 rebels including members and leaders of the Montoneros rebels and People's Revolutionary Army, escaped from the civilian jail in Rawson, in 1972

Later 19 were recaptured and held at the Admiral Zar Naval Base in Trelew. Subsequently, 16 were executed on August 22, 1972 in what was called a failed escape attempt.

A report from Argentina's Crimes Against Humanity Board in September found that between 2008 and July 2012 there were 61 trials for crimes committed by the dictatorship, with 270 convictions. Another 15 cases are under way.

Some 30,000 people were abducted and killed during the 1976 to 1983 military dictatorship, according to human rights organizations.