Conversation so far:
What were some religious issues at the time of Thích Quảng Đức's self-immolation?
President Diệm was a member of the Catholic minority, and pursued discriminatory policies favoring Catholics.
How did the Buddhist community react to President Diệm's policies?
Many officers in the Army of the Republic of Vietnam (ARVN) converted to Roman Catholicism as their military prospects depended on it.
Did non-military people under President Diệm's regime also convert to Roman Catholicism?
Some Buddhist villages converted en masse to receive aid or avoid being forcibly resettled by Diệm's regime.
What happened to Buddhists that didn't convert to Roman Catholicism?
A large crowd of Buddhists protested the ban, defying the government by flying Buddhist flags on the Buddhist holy day of Vesak and marching on the government broadcasting station.

Question: What happened to them?
Self-contained rewrite: What happened to large crowd of Buddhists protesting the Buddhist flag ban on the Buddhist holy day of Vesak?