A junta in Burgos proved unable to set overall strategy; thus, Franco was chosen commander-in-chief at a meeting of ranking generals on 21 September. Mola continued to command the Army of the North and led an unsuccessful effort to take Madrid in October. In a radio address, he described Nationalist sympathizers in the city as a "fifth column" that supplemented his four military columns. The Republican government then proceeded to carry out the mass execution of as many as 2,000 suspected civilian and military supporters of the Nationalists. What was later known as the Paracuellos massacres crushed any potential fifth column.