sentences:  On 10 April, a private was killed in a guerrilla ambush and a policeman was gunned down while standing guard at a hospital.In mid-April, in a major operation conducted against the ERP underground network in the province of Córdoba, the 4th Airborne Infantry Brigade took into custody and forcibly disappeared some 300 activists.On 26 April, inspector general Juan Sirnio of the Tucumán Police was shot dead in his car by unknown perpetrators.