Among those arrested are the leader of the opposition LSD ("Rallyed Social Democrats") party, Chan Po-ying, and a prominent democracy activist, Alexandra Wong, also known as "Grandma Wong."
Po-ying and Wong were reportedly holding flowers and candles during a peaceful demonstration in a shopping area of the city when they were surrounded by officials and taken to police cars.
The massacre has attracted attention in Hong Kong every year, until it was banned in 2020 when a new security law was introduced.
Some of those arrested are now charged with "sedition" and "disorderly conduct," according to Hong Kong police.
This year marks 34 years since the student-led protests in Beijing's Tiananmen Square were violently suppressed. At least several hundred people were killed, according to some reports up to 3,000.