Hecklers at a speech by top mainland official Li Fei were hauled away by security guards yesterday, while police used pepper spray to stop protesters from entering the venue of a forum to discuss the 2017 electoral framework set by Beijing.
"Shame on the central government, Beijing has lost credibility" the protesters at AsiaWorld Expo chanted, holding up signs reading "shameful", amid hissing from the Beijing loyalists who made up the majority of guests.
Li, deputy secretary general of the National People's Congress Standing Committee, had come to Hong Kong to explain Beijing's tough restrictions on the 2017 chief executive election. He looked stern and unperturbed by the interruptions.
He continued his speech until the meeting was stopped while protesting pan-democrats were ejected.
Dressed in black and wearing yellow ribbons, about 20 pan-democrats started yelling slogans shortly after Li, who is also chairman of the Basic Law Committee, started his speech in the conference hall of the exhibition venue near the airport.
Beijing loyalists in the crowd clapped as pan-democrats were expelled, some dragged and others escorted quietly.
"We are here to reflect the anger of millions of Hongkongers who have waited for decades for democracy," Democratic Party chairwoman Emily Lau Wai-hing said as she was led away.
Watch: Protesters and lawmakers react to Beijing's dictum on leadership reform
Outside the hall, police used pepper spray to disperse 20 activists from the radical group Civic Passion, who tried to storm past security staff,
"Police condemned their acts, which endangered public safety and public order," said Senior Superintendent Kwok Pak-chung, district commander for the airport. "They ignored police appeals and warnings, including warning banners. Police had no other option but to take resolute actions and use the appropriate and lowest level of force."
Kwok said pepper spray was used three times in total.
Some 300 protesters from various groups gathered outside the hall, shouting "traitors" and "shame on you" as NPC members including local deputy Maria Tam Wai-chu walked past.
Clashes also broke out between them and a few dozen Beijing supporters, who shouted slogans and displayed placards imploring people to "support the NPC's decision".
In the afternoon, a partially naked protester stole the spotlight as about 100 pro-Beijing protesters gathered in Tim Wa Avenue in Admiralty, as Li attended a press conference at the government offices nearby.
The lone man asked police to give him a spot to protest for the pan-democratic camp before suddenly stripping off almost all of his clothes.
"If Li Fei can be so 'nude' to Hongkongers, why can't we go naked on the street?" yelled the man, who described the central government's rule over Hong Kong as "naked tyranny".
He was subdued by police and later taken away.
At about 11pm dozens of protesters from Civic Passion clashed with police outside the Grand Hyatt hotel in Wan Chai, where Li was staying. Officers took some away but it was not clear if they were arrested.
Watch: Almost nude man protests against NPC's "naked dictatorship"
Additional reporting by Phila Siu, Timmy Sung and Chris Lau