Among those detained were Martin Lee, 81, founder of the Democratic Party founder and a senior barrister; publishing tycoon Jimmy Lai, 71; and former legislator and barrister Margaret Ng, 72, the Associated Press reported.
Democratic legislator Claudia Mo, who was not arrested, said Hong Kong’s Chief Executive Carrie Lam wanted to “introduce a ring of terror in Hong Kong.”
“They are doing whatever they can to try to silence, to take down, the local opposition,” Mo said in a statement.
Police Superintendent Lam Wing-ho told reporters that those arrested were charged with organizing and participating in “unlawful assemblies” last summer and fall. They are due in court on May 18.
Those days involved big, and sometimes violent protests, across the city.
Protesters originally were angry about a now-scrapped bill proposing to send suspects to mainland China for trial. But their activism expanded into demands for full democracy and a public investigation of the use of force by police.
The arrests come after several months of relative calm because of a partial coronavirus lockdown and just as Chinese and city government officials begin pushing for tougher national security laws for Hong Kong.