Castro managed to escape into the Sierra Maestra mountains with as few as 12 fighters, aided by the urban and rural opposition, including Celia Sanchez and the bandits of Cresencio Perez's family. Castro and Guevara then began a guerrilla campaign against the Batista régime, with their main forces supported by numerous poorly armed "escopeteros" and the well-armed fighters of Frank País' urban organization. Growing anti-Batista resistance, including a bloodily crushed rising by Cuban Navy personnel in Cienfuegos, soon led to chaos in the country. At the same time, rival guerrilla groups in the Escambray Mountains also grew more effective. Castro attempted to arrange a general strike in 1958, but could not win support among Communists or labor unions. Multiple attempts by Batista's forces to crush the rebels ended in failure. Castro's forces were able to acquire captured weapons, including 12 mortars, 2 bazookas, 12 machine guns mounted on tripods, 21 light machine guns, 142 M-1 rifles, and 200 Dominican Cristobal submachine guns. The biggest prize for the rebels was a government M4 Sherman tank, which would be used in the Battle of Santa Clara.