The vigil has taken on particular significance in recent years as the semi-autonomous city chafes under Beijing's increasingly authoritarian rule
Hong Kong activists shouted anti-government slogans outside court on Tuesday as more than two dozen high profile democracy campaigners appeared over a banned vigil to mark the Tiananmen Square crackdown.
Tens of thousands of Hong Kongers defied a ban on rallies on June 4 to mark the anniversary of Beijing's deadly suppression of students pushing for democracy.
The annual vigil has been held in Hong Kong for the last three decades and usually attracts huge crowds, but this year's gathering was banned for the first time with authorities citing coronavirus measures -- even though local transmission had largely been halted.
The group of defendants represents a broad section of the pro-democracy movement, from 72-year-old media mogul Jimmy Lai to younger campaigners such as Joshua Wong.
The 26 accused are charged with either participating in or inciting others to take part in an unlawful assembly. The incitement charge carries up to five years in jail.
Activists gathered at West Kowloon Magistrates' Courts ahead of the procedural hearing to shout slogans and display banners defending their right to hold a Tiananmen vigil.
"It's not a crime to mourn June 4," one poster read, while another said: "Oppose political prosecutions, Protest political suppression."
Veteran activist Lee Cheuk-yan, 63, told the crowd over a loudspeaker: "We must reiterate that mourning June 4 is not a crime."
The vigil, traditionally held in Victoria Park, has taken on particular significance in recent years as the semi-autonomous city chafes under Beijing's increasingly authoritarian rule.
Lee added: "Suppression suffered by activists on June 4, 1989, is very similar to what Hong Kong people suffered in the past year."
Some of those charged face separate prosecutions related to last year's huge and often violent pro-democracy protests.
China's leaders have rejected calls to give Hong Kongers universal suffrage, and portrayed the protests as a plot by foreigners to destabilize the motherland.
In late June, Beijing imposed a sweeping national security law aimed at stamping out the demonstrations once and for all.
The legislation targets subversion, secession, terrorism and foreign collusion, with sentences including life in prison.
But its broad phrasing -- such as a ban on encouraging hatred towards China's government -- has sent fear rippling through a city used to being able to speak its mind.