The incident occurred during a period of popular unrest by the Buddhist majority against the Roman Catholic rule of Diệm. Buddhist discontent had grown since the Huế Phật Đản shootings on May 8, 1963. The government decided to selectively invoke a law, prohibiting the display of religious flags, by banning the use of the Buddhist flag on Vesak, the birthday of Gautama Buddha. One week earlier, the Vatican flag had been flown at a celebration for Archbishop Ngô Đình Thục, Diệm's brother. The Buddhists defied the ban, flying their flags on Vesak and holding a demonstration, which was ended with government gunfire and eight or nine deaths. The killings sparked nationwide protests by South Vietnam's Buddhist majority against the policies of Diệm's regime. The Buddhists demanded that Diệm give them religious equality, but with their demands unfulfilled, the protests increased in magnitude. The most notable of these was the self-immolation of Thích Quảng Đức on June 11, which was iconically photographed by the media and became a negative symbol of the Diệm régime.