It’s been years since Hong Kong’s mass arrests of activists devastated its pro-democracy activism.

Hong Kong police on Tuesday arrested six people, including a former organizer of the city’s decades-long annual vigil that commemorated China’s Tiananmen Square crackdown, for allegedly publishing seditious social media posts.

China has promoted Hong Kong's top security official to the territory's No. 2 spot as Beijing clamps down on free speech and political opponents.