On 30 December a bomb exploded at the headquarters of the Argentine Army in Buenos Aires, injuring at least six soldiers. In the eyes of the military, the credibility of the government was now destroyed and the strategy of attrition was bankrupt. The guerrillas had even successfully utilized divers of the Grupo Especial de Combate of the Montoneros: the modern type 42 destroyer was severely damaged by explosives placed under her keel by frogmen of the Montoneros on 22 August 1975 while moored in the port of Ensenada. The damage was so great that the ship remained unseaworthy for several years. By the end of 1975, a total of 137 servicemen and police had been killed that year by left wing guerrillas. Elements within the armed forces, particularly among the junior officers, blamed the weakness of the government and began to seek a leader who they considered was strong enough to ensure a preservation of Argentinian sovereignty, settling on Lieutenant-General Jorge Videla. On 11 February 1976, colonel Raúl Rafael Reyes, the commander of the 601st Air Defence Artillery Group, was killed and two army conscripts (Privates Tempone and Gómez) wounded in an ambush by six ERP guerrillas in the La Plata suburb of Buenos Aires.