Hong Kong police have made their first arrests under a new “anti-protest” law imposed by Beijing, as crowds marked 23 years since the end of British rule.
Nine people were held accused of violating the law, including a man with a pro-independence flag. More than 300 others were detained at a banned rally.
The national security law targets secession, subversion and terrorism with punishments up to life in prison.
Activists say it erodes freedoms but China has dismissed the criticism.
Hong Kong’s sovereignty was handed back to China by Britain in 1997 and certain rights were supposed to be guaranteed for at least 50 years under the “one country, two systems” agreement.