Updated at 8:05 a.m. ET
The Hong Kong government charged 47 democracy advocates Sunday with violating a national security law that prohibits "conspiracy to commit subversion," prompting hundreds of protesters to gather in defiance of the law to show their support.
The activists charged were among a group of more than 50 people arrested in January for organizing and taking part in a primary election last July. The mass arrests last month were the most extensive roundup since the law was introduced in the summer.
The law criminalizes four types of activity: secession, subversion of state power, terrorism and collusion with foreign entities. In practice, it severely curtails whatever autonomy that Hong Kong had previously enjoyed under Chinese rule.
Those arrested were among Hong Kong's most vocal democracy advocates, a group that includes many opposition lawmakers. The group of 39 men and eight women had been asked to check in with police on Sunday in preparation for a court appearance Monday morning. If convicted, they could face life in prison.
According to the South China Morning Post, the charged included Democratic Party chairman Wu Chi-wai; Civic Party leader Alvin Yeung Ngok-kiu; and legal scholar Benny Tai, the architect of July's primary election, which brought more than 600,000 people to the polls.
Activist Joshua Wong, who is currently serving more than a year in prison for organizing a protest, was also charged.
Meanwhile, showing support for the accused, pro-democracy demonstrators dressed in black risked arrest themselves on Monday by coming out on the streets in Hong Kong's West Kowloon area. Hundreds chanted slogans and raised six fingers to symbolize their "five demands, not one less," the South China Morning Post reported. Police in turn raised colored-coded flags to warn that the protest could be illegal and that officers were preparing to use force, the newspaper said.
International observers have expressed concern that China is going to great lengths to stamp out opposition. In a statement, the European Union Office to Hong Kong and Macao said the charges "make clear that legitimate political pluralism will no longer be tolerated" there.
U.S. national security adviser Jake Sullivan wrote that the detentions underscore China's "broken promises to the world about Hong Kong's autonomy & democratic rights. We stand in solidarity with these brave activists." U.K. foreign secretary Dominic Raab said the charges were "deeply disturbing" and that the national security law is "being used to eliminate political dissent rather than restore order - contrary to what the Chinese Government promised."
In the days leading up to Sunday's charges, the activists said goodbye to loved ones, and made peace with their fate. As they entered the police station, many gave statements to the media.
"Democracy is never a gift from heaven. It must be earned by many with strong will," said 33-year-old Jimmy Sham, the BBC reported. Sham, of the Civil Human Rights Front, helped organize major protests in 2019. "We will remain strong and fight for what we want."
NPR's Scott Neuman contributed to this report