Operation Primicia ("Scoop") was a large guerrilla assault that took place on 5 October 1975, in Formosa, Argentina.

It was the largest attack ever launched by the paramilitary group Montoneros, which attempted to seize the barracks of the 29th Forest Infantry Regiment.

As a first step, Montoneros hijacked a flight of Aerolíneas Argentinas from the province of Corrientes (with 102 passengers and six crew).

[3] The acting president of Argentina at that time was Ítalo Lúder, as Isabel Perón had taken a leave of absence.

[4] The military deposed her during the 1976 Argentine coup d'état, and continued the Dirty War during the National Reorganization Process.