 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 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 . 
