Frank Sturgis who offered to train Castro's troops in guerrilla warfare. Castro accepted the offer, but he also had an immediate need for guns and ammunition, so Sturgis became a gunrunner. Sturgis purchased boatloads of weapons and ammunition from Central Intelligence Agency (CIA) weapons expert Samuel Cummings' International Armament Corporation in Alexandria, Virginia. Sturgis opened a training camp in the Sierra Maestra mountains, where he taught Che Guevara and other 26 July Movement rebel soldiers guerrilla warfare. Frank País was also killed, leaving Castro the MR-26-7's unchallenged leader. Although Guevara and Raúl were well known for their Marxist–Leninist views, Castro hid his, hoping to gain the support of less radical revolutionaries. In 1957 he met with leading members of the Partido Ortodoxo, Raúl Chibás and Felipe Pazos, authoring the Sierra Maestra Manifesto, in which they demanded that a provisional civilian government be set up to implement moderate agrarian reform, industrialization, and a literacy campaign before holding multiparty elections. As Cuba's press was censored, Castro contacted foreign media to spread his message; he became a celebrity after being interviewed by Herbert Matthews, a journalist from The New York Times. Reporters from CBS and Paris Match soon followed. Castro's guerrillas increased their attacks on military outposts, forcing the government to withdraw from the Sierra Maestra region, and by spring 1958, the rebels controlled a hospital, schools, a printing press, slaughterhouse, land-mine factory and a cigar-making factory. By 1958, Batista was under increasing pressure, a result of his military failures coupled with increasing domestic and foreign criticism surrounding his administration's press censorship, torture, and extrajudicial executions. Influenced by anti-Batista sentiment among their citizens, the US government ceased supplying him with weaponry. The opposition called a general strike, accompanied by armed attacks from the MR-26-7. Beginning on 9 April, it received strong support in central and eastern Cuba, but little elsewhere. Batista responded with an all-out-attack, Operation Verano, in which the army aerially bombarded forested areas and villages suspected of aiding the militants, while 10,000 soldiers commanded by General Eulogio Cantillo surrounded the Sierra Maestra, driving north to the rebel encampments. Despite their numerical and technological superiority, the army had no experience with guerrilla warfare, and Castro halted their offensive using land mines and ambushes. Many of Batista's soldiers defected to Castro's rebels, who also benefited from local popular support. In the summer, the MR-26-7 went on the offensive, pushing the army out of