In mid-2020, Beijing imposed a National Security Law (NSL) to stamp out dissent in the southern Chinese city, which had been rocked by pro-democracy unrest.
There have been few public protests against official policy since then, due to a combination of the crackdown and social-distancing measures to counter the Covid-19 pandemic.
As the first officially authorised protest against a government plan since the coronavirus measures were lifted, it offered an indication of the measure of dissent still allowed in the city.
Police required organisers to follow stringent conditions including capping numbers at 100, making participants wear number tags around their necks, and surrounding the crowd with a cordon, with media separated from marchers.
Officers closely examined banners and placards for "politically sensitive and seditious words", said protest organiser Cyrus Chan.
