Dozens of police officers walked alongside veteran pro-democracy activist Leung Kwok Hung, League of Social Democrats chairman Raphael Wong and two other activists who held a banner that read "there is no national day celebration, only national mourning".
"I hope that Hong Kong people can continue (calling) for the five demands, not one less. I hope that everyone can struggle till the end also the national security, that is meant to be 'safeguarding the country', which actually strips our human rights, should be removed," Leung told reporters.
A national security law imposed by Beijing on June 30, which punishes what authorities see as subversion, secession, foreign interference and terrorism with up to life imprisonment. Critics of the law say it erodes any remaining freedoms the former British colony has, while supporters say it will bring stability after last year's anti-government protests. Thousands of officers have been deployed across the city as calls for protests spread online.