There had been no elections since 1966 , and armed struggle groups came into existence , such as the '' Ejército Revolucionario del Pueblo '' ( ERP , the armed wing of the Workers ' Revolutionary Party , PRT ) , the Catholic nationalist Peronists Montoneros and the '' Fuerzas Armadas Revolucionarias '' ( FAR ) . In August 1972 , an attempt by several revolutionary members to escape from prison , headed by Mario Roberto Santucho ( PRT ) , was followed by what became known as the Trelew massacre . Fernando Vaca Narvaja , Roberto Quieto , Enrique Gorriarán Merlo and Domingo Menna managed to complete their escape , but 19 others were re-captured . 16 of them , members of the Montoneros , the FAR , and the ERP , were killed , and 3 managed to survive . On the same night of August 22 , 1972 , the junta approved law 19,797 , which proscribed any information concerning guerrilla organizations . The massacre led to demonstrations in various cities
Trelew massacre
Trelew massacre
Argentine Revolution