Some 3,500 soldiers of the 5th Mountain Infantry Brigade, and two companies of elite commandos, placed under the command of Brigadier-General Acdel Vilas began immediately deploying in the Tucumán mountains in "Operacion Independencia", joined later by 1,500 more troops from the 4th Airborne Infantry Brigade and 8th Mountain Infantry Brigade. The pattern of the war was largely dictated by the nature of the terrain, the mountains, rivers and extensive jungle denying both sides easy movement. The A-4B Skyhawk fighters and B.62 Canberra bombers of the Argentine Air Force were used for offensive air support while the North American T-34 and FMA IA 58 Pucará served as a light ground-attack and reconnaissance aircraft. While fighting the guerrilla in the jungle and mountains, Vilas concentrated on uprooting the ERP support network in the towns, using state terror tactics later adopted nationwide during the "Dirty War", as well as a civic action campaign. By July, the Argentine Army commandos were mounting search-and-destroy missions. The Army special forces discovered Santucho's base camp in August, then raided the ERP urban headquarters in September. Most of the "Compania del Monte's" headquarters staff was killed in October and the remainder dispersed by the end of the year. While most of the leaders of the movement were killed outright, many of the captured ERP subalterns and sympathizers were incarcerated during the government of Isabel Martínez de Perón, but little mercy was shown to captured guerrillas and civilian collaborators during the military dictatorship.