 On 15 February 1977, army corporal Osvaldo Ramón Ríos was killed after his patrol came under fire from a group of Montoneros that had barricaded themselves inside a house in the Ezpeleta suburb of Buenos Aires.That same month, Ireneo Garnica and Alejandro Díaz, both railway workers who had refused to participate in a strike, were killed when Montoneros threw a bomb at them in the suburb of Quilmes in Buenos Aires.On 19 March 1977, 45-year-old Sergeant Martín A. Novau from the Federal Police was shot and killed while he was repairing a police car in a work shop in Buenos Aires.