In 1963, South Vietnam faced civil unrest in the face of Buddhist protests against discrimination by the Catholic-oriented Diệm regime. In the wake of the shootings of nine Buddhist protesters on the birthday of Gautama Buddha for defying a ban on the Buddhist flag, mass protests calling for religious equality erupted around the country. With opposition to Diệm growing, Nhu plotted an attack against Xá Lợi Pagoda, the largest Buddhist centre in Saigon, where the movement was organizing its activities. Tung's special forces under Nhu's orders were responsible for the raid on 21 August 1963, in which 1,400 monks were arrested and hundreds were estimated to have been killed, as well as extensive property damage. These attacks were replicated across the country in a synchronised manner. Following the attacks, U.S. officials threatened to withhold aid to the Special Forces unless they were used in fighting communists, rather than attacking dissidents.