After the Huế Phật Đản shootings on May 8 , civil unrest broke out in South Vietnam . Nine Buddhists were shot by the Roman Catholic regime of President Ngô Đình Diệm after defying a government ban on the flying of Buddhist flags on Vesak , the birthday of Gautama Buddha and marching in an anti-government protest . Following the shootings , Buddhist leaders began to lobby Diệm for religious equality and compensation and justice for the families of the victims . With Diệm remaining recalcitrant , the protests escalated . The self-immolation of Buddhist monk Thích Quảng Đức at a busy Saigon intersection became a public relations disaster for the Diệm regime , as photos of the event made front-page headlines worldwide and became a symbol of Diệm 's policies . As protests continued , the Army of the Republic of Vietnam ( ARVN ) Special Forces loyal to Diệm 's brother Ngô Đình Nhu conducted the Xá Lợi Pagoda raids on August 21 , leaving a death toll estimated to be up to several hundred and causing extensive damage under the declaration of martial law . Universities and high schools were closed amid mass pro-Buddhist protests . In the meantime , the fight against the Viet Cong insurgency had begun to lose intensity amid rumors of sectarian infighting amongst ARVN troops . This was compounded by the plotting of a coup by various ARVN officers , which distracted attention from the insurgency . After the pagoda raids , the Kennedy administration sent Cable 243 to the US Embassy , Saigon , ordering an exploration of alternative leadership possibilities
Xá Lợi Pagoda raids
Xá Lợi Pagoda raids
Krulak–Mendenhall mission