What does detaining someone over an unlawful (per the written law) protest have anything to do with corruption?
Corruption involves bribes, selective enforcement of the law, unethical favoritism when it comes to legal decisions, "favors", etc.
Your links just describe people participating in a protest that was against the law on the books, and then that law being enforced upon them. You can call that specific law unfair, undemocratic, authoritarian, etc., but what's the corruption angle here?
> a: dishonest or illegal behavior especially by powerful people (such as government officials or police officers) : depravity
> b: inducement to wrong by improper or unlawful means (such as bribery); the corruption of government officials
> c: a departure from the original or from what is pure or correct the corruption of a text; the corruption of computer files
> d: decay, decomposition; the corruption of a carcass
As far as I can tell the law was passed by the legislature, the police enforced the law, they weren't bribed to not enforce it or to enforce it.
Seems like the whole system worked correctly, legally and without corruption of any kind.