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Student protesters dancing at Tiananmen Square before the massacre, Beijing, China, 1989
(lemmy.world)
https://en.wikipedia.org/wiki/1989_Tiananmen_Square_protests_and_massacre
The protests lasted over a month; the massacre ended them in a flood of state-sponsored murder.
I don't know if you know this but there's a link in the post to a Wikipedia article about it, with sources at the bottom