China didn't have anti protest gear at that time, that's why they took tanks over there, there weren't any of those trucks that shoot water and the like, basically what they had where guns and the military since the police wasn't that well equipped. And as I said in me previous comment, they do acknowledge it, as a counterrevolutionary movement that must be stopped. Think about it in the same way that how the US handled the Black Panthers, they were basically risking the status quo (the bourgeoisie staying in power) and they effectively suppress them through different means.