What group launched anti-diem protests in south vietnam during the summer of 1963 that included street demonstrations and hunger strikes?

The answer to that question is Buddhist monks.  This began in 1963 when protesters where shot for demonstrating against the Buddhist’s Flag ban.  This led to numerous protests by Buddhist monks directed against President Ngo Dinh Diem. Diem was a Catholic whose policies were partial to the Catholic minority.  Majority of the Vietnamese population was Buddhist and many were oppressed by his policies.  As a result many monks held protests against his administration’s policies.  One such demonstration led monks to set themselves on fire.  Later on a coup overthrew Diem which led to his arrest and assassination on November 12, 1963.