Hundreds of pro-democracy protesters have gathered at a court in Hong Kong where 47 activists face charges of "conspiracy to commit subversion".
Police have told the crowds at the West Kowloon Magistrates Court that they are in breach of the controversial national security law and face fines, reports the BBC.
Beijing enforced the law criminalising "subversive" acts last year, saying it was needed to bring stability.
Critics say it has silenced dissent and stripped Hong Kong of its autonomy.
The law came into force after a series of mass pro-democracy protests in 2019, some of which turned violent.
The 47 pro-democracy activists appearing in court on Monday - 39 men and eight women, aged between 23 and 64 - were among a group of 55 people arrested in dawn raids last month.
They had helped run an unofficial "primary" election last June to pick opposition candidates for 2020 legislative elections, which were then postponed.
Chinese and Hong Kong officials say the primary was an attempt to overthrow the government.On Monday, police officers were deployed to control the crowds as supporters queued for seats at the court hearing, many dressed in black - the colour protesters have been wearing while demonstrating.
Some chanted slogans including "liberate Hong Kong, revolution of our times" and "fight for freedom, stand with Hong Kong".
Police warned those gathered to split into groups of no more than four or face fines.