Disgruntled by their demotions, Phát and Đức launched a coup attempt before dawn on September 13, having recruited ten army battalions.[16] They gained the support of Colonel Lý Tòng Bá, the head of the 7th Division's armored section,[17] and Colonel Dương Hiếu Nghĩa, a tank commander who had been one of Diệm's assassins.[18] It appeared at this stage that the coup was supported by Catholic and Đại Việt elements.[19] Another member of the conspiracy was Colonel Phạm Ngọc Thảo, who while a Catholic, was a communist spy trying to maximize infighting at every possible opportunity.[18][20]